November 27, 2013
A force that intricately links the rotation of the Earth with the direction of weather patterns in the atmosphere has been shown to play a crucial role in the creation of the hypnotic patterns created by the skirts of the Whirling Dervishes.
This is according to an international group of researchers who have demonstrated how the Coriolis force is essential for creating the archetypal, and sometimes counterintuitive, patterns that form on the surface of the Whirling Dervishes skirts by creating a set of very simple equations which govern how fixed or free-flowing cone-shaped structures behave when rotating.
The equations, which have been published today, 27 November, in the Institute of Physics and German Physical Society’s New Journal of Physics, were able to reproduce the sharp peaks and gentle troughs that appear along the flowing surface of the Dervishes’ skirts and showed a significant resemblance to real-life images.
The Whirling Dervishes, who have become a popular tourist attraction in Turkey, are a religious movement who commemorate the 13th-century Persian poet, Rumi, by spinning on the spot and creating mesmerising patterns with their long skirts. A YouTube video of the Whirling Dervishes in action can be viewed here:
Co-author of the study James Hanna, from Virginia Polytechnic Institute and State University, said: “The dancers don’t do much but spin around at a fixed speed, but their skirts show these very striking, long-lived patterns with sharp cusp-like features which seem rather counterintuitive.”
Hanna, along with Jemal Guven at the Universidad Nacional Autónoma de México and Martin Michael Müller at Université de Lorraine, found that it was the presence of a Coriolis force that was essential in the formation of the different patterns.
The Coriolis effect accounts for the deflection of objects on a rotating surface and is most commonly encountered when looking at the Earth’s rotations and its effect on the atmosphere around it. The rotation of the Earth creates the Coriolis force which causes winds to be deflected clockwise in the Northern Hemisphere and anti-clockwise in the Southern Hemisphere – it is this effect which is responsible for the rotation of cyclones.
“Because the sheet is conically symmetric, material can flow along its surface without stretching or deforming. You can think of the rotating Earth, for example, with the air of the atmosphere free to flow around it.
“The flow of a sheet of material is much more restrictive than the flow of the atmosphere, but nonetheless it results in Coriolis forces. What we found was that this flow, and the associated Coriolis forces, plays a crucial role in forming the dervish-like patterns,” Hanna continued.
By providing a basic mathematical description of the spinning skirts of the Dervishes, the researchers hope their future research will discern how different patterns are selected, how stable these patterns are and if gravity or any other effects make a qualitative difference.
From Wednesday 27 November, this paper can be downloaded fromhttp://iopscience.iop.org/1367-2630/15/11/113055/article
November 25, 2013
One of the smallest parts of the brain is getting a second look after new research suggests it plays a crucial role in decision making.
A University of British Columbia study published today in Nature Neuroscience says the lateral habenula, a region of the brain linked to depression and avoidance behaviors, has been largely misunderstood and may be integral in cost-benefit decisions.
“These findings clarify the brain processes involved in the important decisions that we make on a daily basis, from choosing between job offers to deciding which house or car to buy,” says Prof. Stan Floresco of UBC’s Dept. of Psychology and Brain Research Centre (BRC). “It also suggests that the scientific community has misunderstood the true functioning of this mysterious, but important, region of the brain.”
In the study, scientists trained lab rats to choose between a consistent small reward (one food pellet) or a potentially larger reward (four food pellets) that appeared sporadically. Like humans, the rats tended to choose larger rewards when costs – in this case, the amount of time they had to wait before receiving food–were low and preferred smaller rewards when such risks were higher.
Previous studies suggest that turning off the lateral habenula would cause rats to choose the larger, riskier reward more often, but that was not the case. Instead, the rats selected either option at random, no longer showing the ability to choose the best option for them.
The findings have important implications for depression treatment. “Deep brain stimulation – which is thought to inactivate the lateral habenula — has been reported to improve depressive symptoms in humans,” Floresco says. “But our findings suggest these improvements may not be because patients feel happier. They may simply no longer care as much about what is making them feel depressed.”
Floresco, who conducted the study with PhD candidate Colin Stopper, says more investigation is needed to understand the complete brain functions involved in cost-benefit decision processes and related behaviour. A greater understanding of decision-making processes is also crucial, they say, because many psychiatric disorders, such as schizophrenia, stimulant abuse and depression, are associated with impairments in these processes.
The lateral habenula is considered one of the oldest regions of the brain, evolution-wise.
November 22, 2013
Scientists using a particle detector made of ice at the South Pole have found the first indication of high-energy neutrinos that originate outside of the solar system.
“This is a huge result. It could mark the beginning of neutrino astronomy,” said Darren Grant, assistant professor of physics at the University of Alberta, who leads the IceCube Collaboration effort in Canada. The collaboration is led by the University of Wisconsin-Madison and involves 250 physicists and engineers from the United States, Germany, Sweden, Belgium, Switzerland, Japan, New Zealand, Australia, the U.K. and Canada.
Neutrino researchers have been looking to the sky for decades to learn more about the elusive particles. Until now, scientists have seen low-energy neutrinos that originate in Earth’s atmosphere, neutrinos from farther out within the solar system, and neutrinos from one rare nearby supernova, known as 1987A.
The neutrinos observed by IceCube are different. “They are at a significantly higher energy level than those produced by the previously measured sources,” Grant said. If the observation is confirmed, scientists will have found high-energy neutrinos from yet-to-be confirmed cosmic sources.
Sensors embedded deep in IceCube – a particle detector made from one cubic kilometre of ice in Antarctica – were designed to detect extraterrestrial neutrinos. From there, researchers relied on access to the Jasper computer cluster located at the U of A, managed by the WestGrid consortium as part of Compute Canada’s national platform of advanced research computing infrastructure. The computational studies to analyze the data often consumed 1,000 CPUs (central processing units) in one day, with a peak use of 1,900 CPUs. In total, the project amassed more than 600,000 CPU hours on WestGrid’s cluster.
“We wouldn’t have been able to perform these studies without the WestGrid cluster in the time we did it,” said Claudio Kopper, one of the Madison post-doctoral fellows who developed the analysis. “When I started, getting over 1,000 cores in parallel on Jasper was not uncommon. Having a fast turnaround time with many available cores turned out to be extremely valuable.”
“This is an exciting milestone in neutrino research and we’re pleased that Jasper, one of WestGrid’s most powerful computing clusters, could support the work that led to this discovery,” said Lindsay Sill, interim executive director of WestGrid. “This is an excellent example of how access to high performance computing resources enables scientists to tackle data-intensive research questions and push the boundaries of what we thought was possible.”
U of A graduate students helped to prepare this set of data for analysis. “Tania Wood and Sarah Nowicki are working on the calibrations for the detector to better understand how the light produced in the neutrino interactions travels through the glacier,” said Grant. Wood and Nowicki are also doing work that will have more central significance to upcoming observations being made at lower energy levels. Three U of A undergraduate students who assisted in the IceCube detector calibrations and data handling are also co-authors of the paper: Stephanie Bohaichuk, Chris Sheramata and Dylan Grandmont.
Grant was recently named co-leader of a potential major upgrade to the IceCube detector called PINGU (Precision IceCube Next Generation Upgrade).
“We are still learning about the neutrino as one of nature’s fundamental particles,” said Grant. “It was only 15 years ago that we discovered neutrinos have a small mass, but we have yet to learn which neutrino is heaviest, what we call the hierarchy. This is what we are designing PINGU to provide: a first definitive measurement.”
Details of the research were published Nov. 22 in the peer-reviewed journal Science.
November 19, 2013
A famous math problem that has vexed mathematicians for decades has met an elegant solution by Cornell University researchers. Graduate student Yash Lodha, working with Justin Moore, professor of mathematics, has described a geometric solution for the von Neumann-Day problem, first described by mathematician John von Neumann in 1929.
Lodha presented his solution at the London Mathematical Society’s Geometric and Cohomological Group Theory symposium in August, and has submitted the work to a journal. “People were very excited by this,” Lodha said. “[The solution] is natural and compelling enough to study for its own sake.”
Lodha works in the field of geometric group theory. A group is a mathematical construct that describes the notion of the symmetries of an object, whether it’s a physical object or a theoretical space. For example, a polygon has rotational as well as reflectional symmetries, all of which, together with the operation of composition, form what’s called a finite group, because the polygon can be described as a finite sequence of operations that reflect its symmetries.
Formally, a group can be described as words in an alphabet together with a set of rules that are called “relations.” Group theorists, Lodha said, are like biologists who classify species; mathematicians try to categorize groups that have properties A, B or C – but is there one that has A but not C?
The inspiration for Lodha’s work originated in the early 20th century, when mathematicians first proved that a ball that exists in three-dimensional space can be chopped into a finite number of pieces – “like tearing up a piece of paper without stretching or squeezing,” Lodha explained – and can be reassembled, like a jigsaw puzzle, into two balls, each the size of the original ball. This is known as the Banach-Tarski paradox.
von Neumann, in studying this paradox, was the first to describe the reason behind it: He attributed it not to the geometry of 3-D space, but to the algebraic properties of the symmetries inherent to the sphere. He was the first to isolate this property, which mathematicians today call “non-amenability.”
von Neumann further observed that if a group contains free groups, which are groups that have a finite alphabet and no rules, then it must be non-amenable. He posed the question of whether the opposite is true – are there groups that do not contain free groups and are also non-amenable? The problem, later popularized by M.M. Day, waited another 40 years before mathematician Alexander Olshanskii cracked it, although Olshanskii’s group had an infinite set of rules.
Another two decades went by before Olshanskii and Mark Sapir supplied another solution in response to the von Neumann-Day problem. This time, their example was governed by a finite, but large set of rules – close to 10,200. It also lacked a natural geometric model. So mathematicians probed further for a group with a finite set of rules, that is non-amenable and does not contain free groups.
For the first time, Lodha describes a group that has only nine rules, a natural geometric model, is non-amenable and does not contain free groups.
Advances in mathematics are almost always incremental and build upon previous work, Lodha said. To complete this work, among his most valuable insights was one first described by the late Bill Thurston, Fields medalist and Cornell’s Jacob Gould Schurman Professor of Mathematics, which involved a way of expressing the group in a different light, as a “continued fractions model.”
Lodha’s work also builds heavily on work by Nicolas Monod, who constructed a geometrically oriented, but not finitely presented, counterexample to the von Neumann-Day problem. Lodha and Moore’s contribution was to isolate a finitely presented subgroup, with only nine relations, of Monod’s example.
Further work on the group, which doesn’t yet have a name, could make the solution to the von Neumann-Day problem even stronger: by isolating stronger finiteness conditions for proving that the group has a finite number of rules.
The research was supported by the National Science Foundation.
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November 13, 2013
With the rise of online open course platforms such as Khan Academy, MIT OpenCourseWare and iTunes U, it has never been easier to teach yourself everything from American history to semiconductor manufacturing. These courses enable students to advance at their own pace while accessing the limitless resources available on the internet for supplemental material.
But there’s a glaring exception to this cornucopia of courseware: Online physics classes that enable students to interact with a real physical experiment. While excellent online sites like Phet Interactive Simulations have developed virtual labs that simulate laboratory environments, there is no substitute for actual live experiments.
At the U.S. Department of Energy’s Princeton Plasma Physics Laboratory (PPPL), we’ve developed software for an experiment that can be observed and controlled from anywhere in the world.
The user can operate the experiment with a set of controls, shown on the left side of the screen, and watch the effect on the apparatus at PPPL using the web stream video, shown on the right. This “Remote Glow Discharge Experiment (RGDX)” consists of three main components:
- A live-streaming video that constantly observes an experimental apparatus housed at PPPL.
- A set of online controls.
- Information that explains what the user observes and controls, plus more in-depth resources that explore plasma and its uses.
The RGDX consists of a hollow glass tube with air held under vacuum. Supplying a voltage of up to 2000V generates a glow discharge within. The user has control of the pressure inside the tube, the voltage supplied to the plasma and of the strength of an electromagnet surrounding the tube. Users are guided through steps that gradually increase their level of engagement and introduce them to new physical concepts and topics. If the user is interested in the physics behind the voltages, pressures and magnets, further explanations are given for each topic.
Audiences for the RGDX can range from someone simply interested in controlling a physical apparatus from afar, to an undergraduate or graduate student who wants to study phenomena such as instabilities in plasma or the physics behind plasma breakdown voltages. The RGDX can be used as a novel experimental component of either an online or in-class physics course, and the software can be adapted to a wide array of experiments.
October 31, 2013
Scientists from the Helmholtz Zentrum Muenchen and the Technische Universitaet Muenchen, together with scientists in the USA, have developed a new therapeutic approach for treatment of Type 2 diabetes. A novel single molecule hormone, which acts equally on the receptors of the insulin-stimulating hormones GLP-1 and GIP, was observed to reduce weight and improve blood sugar.
The results have now been published in the medical journal Science Translational Medicine, and include data from successful clinical studies in partnership with the pharmaceutical company Roche.
GLP-1 (glucagon-like peptide 1) and GIP (gastric inhibitory peptide) are hormones that are formed by the digestive tract and that control food intake and numerous metabolic processes. When glucose (sugar) is ingested, these hormones primarily lead to increased insulin release and subsequent reduction in blood sugar, but they also affect appetite regulation and fat burning.
Some of the actions, which are combined in one molecule for the first time, are already in use for the treatment of type 2 diabetes. GLP-1 analogues, as well as DPP4 (dipeptidyl peptidase 4) inhibitors, which are thought to enhance GLP-1 action, are used to reduce blood sugar. A HMGU and TUM team led by Dr. Brian Finan and Prof. Dr. Matthias Tschöp at the Helmholtz Diabetes Center, working with Richard DiMarchi from Indiana University and colleagues from the University of Cincinnati, have now succeeded in developing a molecular structure that combines the effects of the two hormones. These novel molecules simultaneously stimulate two receptors (GLP-1 and GIP) and consequently maximize metabolic effects compared to each of the individual molecules, or currently available medicines that are based on individual intestinal hormones.
The newly discovered GLP-1/GIP co-agonists lead to improved blood sugar levels and to a significant weight loss and lower blood fat. Importantly, the researchers observed that the new substance also improved metabolism in humans, in addition to beneficial effects they discovered in several animal models. At the same time, there are indications that possible adverse effects, the most frequent of which are gastrointestinal complaints, are less common and less pronounced with this approach than with the individual hormones.
“Our results give us additional confidence that our combinatorial approach of modulating brain regulatory centers via natural gut hormone signals has superior potential for a transformative diabetes treatment”, explains Prof. Tschöp. He adds a note of caution however: “Still, this approach has to go through several more years of intense research, clinical testing, and safety evaluations, before these substances may become available for patients”. Dr. Finan, the first author of the study, points out that there may be unprecedented potential: “We are quite excited about this new multi-functional agent approach and believe it could become an integral part of a next generation of personalized therapies for type 2 diabetes, as the ratio of the GLP-1 and GIP signal strengths could be adjusted depending on the individual needs of patients.” The studies which were just published in Science Translational Medicine are perfectly aligned with the research objective of at the Helmholtz Zentrum München, partner of the German Center for Diabetes Research (DZD), which is to establish new approaches to the diagnosis, therapy and prevention of civilization’s major widespread diseases and to further develop these approaches as quickly as possible in the context of translational research in order to provide specific benefits for society.
Original publication: Finan, B. et al. (2013). Novel Unimolecular Dual-Incretins Maximize Metabolic Benefits in Rodents, Monkeys, and Humans, Science Translational Medicine, doi: 10.1126/scitranslmed.3007218
As German Research Center for Environmental Health, Helmholtz Zentrum München pursues the goal of developing personalized medical approaches for the prevention and therapy of major common diseases such as diabetes mellitus and lung diseases. To achieve this, it investigates the interaction of genetics, environmental factors and lifestyle. The Helmholtz Zentrum München has about 2,100 staff members and is headquartered in Neuherberg in the north of Munich. Helmholtz Zentrum München is a member of the Helmholtz Association, a community of 18 scientific-technical and medical-biological research centers with a total of about 34,000 staff members.
The German Center for Diabetes Research (DZD) brings together experts in the field of diabetes research and interlinks basic research, epidemiology and clinical applications. Members are the German Diabetes Center in Düsseldorf, the German Institute of Human Nutrition (DIfE) in Potsdam-Rehbrücke, Helmholtz Zentrum München – German Research Center for Environmental Health, the Paul Langerhans Institutes of the University Hospital Carl Gustav Carus in Dresden and the University of Tübingen, as well as the Gottfried Wilhelm Leibniz Association and the Helmholtz Association of German Research Centres. The objective of the DZD is to find answers to open questions in diabetes research by means of a novel, integrative research approach and to make a significant contribution to improving the prevention, diagnosis and treatment of diabetes mellitus.
The Institute of Diabetes and Obesity (IDO) studies the diseases of the metabolic syndrome by means of systems biological and translational approaches on the basis of cellular systems, genetically modified mouse models and clinical intervention studies. It seeks to discover new signaling pathways in order to develop innovative therapeutic approaches for the personalized prevention and treatment of obesity, diabetes and their concomitant diseases. IDO is part of the Helmholtz Diabetes Center (HDC).
October 28, 2013
As the U.S. makes new plans for disposing of spent nuclear fuel and other high-level radioactive waste deep underground, geologists are key to identifying safe burial sites and techniques. Scientists at The Geological Society of America (GSA) meeting in Denver will describe the potential of shale formations; challenges of deep borehole disposal; and their progress in building a computer model to help improve understanding of the geologic processes that are important for safe disposal of high-level waste.
In the United States, about 70,000 metric tons of spent commercial nuclear fuel are located at more than 70 sites in 35 states. Shales and other clay-rich (argillaceous) rocks have never been seriously considered for holding America’s spent nuclear fuel, but it is different overseas. France, Switzerland, and Belgium are planning to put waste in tunnels mined out of shale formations, and Canada, Japan, and the United Kingdom are evaluating the idea.
At the GSA meeting, U.S. Geological Survey hydrogeology expert C.E. Neuzil of Reston, Virginia, will report that some shales are so impermeable that there is little risk of radioactivity from buried nuclear waste reaching ground or surface water.
“This is usually difficult to demonstrate,” Neuzil says, “but some shales have natural groundwater pressure anomalies that can be analyzed — as if they were permeability tests — on a very large scale.” This capability was shown recently at the Bruce Nuclear Site, explains Neuzil, a proposed low/intermediate waste repository 1,200 feet underground in Ontario, Canada. Argillaceous rocks have additional attractive qualities, Neuzil says: They are common, voluminous, and tend to be tectonically quiet — meaning no earthquakes to crack the walls of a fuel-rod burial chamber.
Another disposal option for nuclear waste is deep boreholes. The 2012 presidential Blue Ribbon Commission on America’s Nuclear Future recommended more research, and the U.S. Department of Energy is now developing an R&D plan. However, the U.S. Nuclear Waste Technical Review Board (NWTRB) has statutory responsibility for evaluating the technical validity of DOE’s nuclear waste activities, and is on the record with the position that deep boreholes present many technical challenges and studying them “should not delay higher priority research on a mined geologic repository.”
At next week’s GSA meeting, Review Board senior staff professional Bret W. Leslie and Stanford University geophysicist Mary Lou Zoback, an NWTRB member, will present the board’s assessment of:
- the technical feasibility of drilling a borehole of the proposed depth (3 miles) and width (about 20 inches), which has never been done;
- the exposure risk for workers, who would have to repackage waste currently stored in canisters that are wider than the width of the proposed boreholes;
- the reliability of existing sealing technology; and
- the large number of deep boreholes that would be required — nearly 700.
Whether nuclear waste winds up in tunnels, boreholes or both, the planning will be helped by new analytical tools. One is a new computer model that will evaluate the behavior of various forms of nuclear waste, and waste containers and barriers, if stored in various rocks. The model is being developed under the auspices of the Center for Nuclear Waste Regulatory Analyses (CNWRA), the NRC’s federally funded research and development center, and will be described at the GSA meeting by NRC performance analyst Jin-Ping Gwo.
October 25, 2013
In Australia’s Western Desert, Aboriginal hunters use a unique method that actually increases populations of the animals they hunt, according to a study co-authored by Stanford Woods Institute-affiliated researchers Rebecca and Doug Bird. Rebecca Bird is an associate professor of anthropology, and Doug Bird is a senior research scientist.
The study, published Oct. 23 in Proceedings of the Royal Society B, offers new insights into maintaining animal communities through ecosystem engineering and co-evolution of animals and humans. It finds that populations of monitor lizards nearly double in areas where they are heavily hunted. The hunting method – using fire to clear patches of land to improve the search for game – also creates a mosaic of regrowth that enhances habitat. Where there are no hunters, lightning fires spread over vast distances, landscapes are more homogenous and monitor lizards are more rare.
“Our results show that humans can have positive impacts on other species without the need for policies of conservation and resource management,” Rebecca Bird said. “In the case of indigenous communities, the everyday practice of subsistence might be just as effective at maintaining biodiversity as the activities of other organisms.”
Martu, the aboriginal community the Birds and their colleagues have worked with for many years, refer to their relationship with the ecosystem around them as part of “jukurr” or dreaming. This ritual, practical philosophy and body of knowledge instructs the way Martu interact with the desert environment, from hunting practices to cosmological and social organization. At its core is the concept that land must be used if life is to continue. Therefore, Martu believe the absence of hunting, not its presence, causes species to decline.
While jukurr has often been interpreted as belonging to the realm of the sacred and irrational, it appears to actually be consistent with scientific understanding, according to the study. The findings suggest that the decline in aboriginal hunting and burning in the mid-20th century, due to the persecution of aboriginal people and the loss of traditional economies, may have contributed to the extinction of many desert species that had come to depend on such practices.
The findings add to a growing appreciation of the complex role that humans play in the function of ecosystems worldwide. In environments where people have been embedded in ecosystems for millennia, including areas of the U.S., tribal burning was extensive in many types of habitat. Many Native Americans in California, for instance, believe that policies of fire suppression and the exclusion of their traditional burning practices have contributed to the current crisis in biodiversity and native species decline, particularly in the health of oak woodland communities. Incorporating indigenous knowledge and practices into contemporary land management could become important in efforts to conserve and restore healthy ecosystems and landscapes.
The study was funded by the National Science Foundation.
October 24, 2013
Stem cells are crucial for the continuous generation of new cells. Although the importance of stem cells in fuelling plant growth and development still many questions on their tight molecular control remain unanswered. Plant researchers at VIB and Ghent University discovered a new step in the complex regulation of stem cells. Today, their results are published online in this week’s issue of Science Express.
Lieven De Veylder: “Our data suggest that certain organizing stem cells in plant roots are less sensitive for DNA-damage. Those cells hold an original and intact DNA copy which can be used to replace damaged cells if necessary. Animals rely on a similar mechanism but most likely plants have employed this in a more optimized manner. This could explain why many plants can live for more than hundreds of years, while this is quite exceptional for animals.”
Quiescent organisers of plant growth
Plant growth and development depend on the continuous generation of new cells. A small group of specialized cells present in the growth axes of a plant is driving this. These so-called stem cells divide at a high frequency and have the unique characteristic that the original mother cell keeps the stem cell activity while the daughter cell acquires a certain specialization. Besides these stem cells, plant roots also harbor organizing cells. These organizing cells divide with a three- to ten-fold lower frequency, therefore often referred to as quiescent center cells. The organizing cells control the action of the surrounding stem cells and can replace them if necessary.
A new molecular network
For almost 20 years, scientists all over the world have been studying the action of the stem cells and that of their controlling organizing cells. Until now it was not known how quiescent and actively dividing cells could co-exist so closely and which mechanisms are at the basis of the quiescent character. Plant researchers at VIB and Ghent University have now identified a new molecular network that increases our understanding of stem cell regulation and activity. Central in this process is the discovery of a new protein, the ERF115 transcription factor. The scientists demonstrated that the organizing cells barely divide because of the inhibition of ERF115 activity. When the organizing cells need to divide to replace damaged surrounding stem cells, ERF115 gets activated. ERF115 then stimulates the production of the plant hormone phytosulfokine which in turn activates the division of the organizing cells. Thus, the ERF115-phytosulfokine network acts as a back-up system during stress conditions which are detrimental for the activity of stem cells.
October 21, 2013
Researchers at Columbia University Medical Center (CUMC) have devised a hair restoration method that can generate new human hair growth, rather than simply redistribute hair from one part of the scalp to another. The approach could significantly expand the use of hair transplantation to women with hair loss, who tend to have insufficient donor hair, as well as to men in early stages of baldness. The study was published today in the online edition of the Proceedings of the National Academy of Sciences (PNAS).
“About 90 percent of women with hair loss are not strong candidates for hair transplantation surgery because of insufficient donor hair,” said co-study leader Angela M. Christiano, PhD, the Richard and Mildred Rhodebeck Professor of Dermatology and professor of genetics & development. “This method offers the possibility of inducing large numbers of hair follicles or rejuvenating existing hair follicles, starting with cells grown from just a few hundred donor hairs. It could make hair transplantation available to individuals with a limited number of follicles, including those with female-pattern hair loss, scarring alopecia, and hair loss due to burns.”
According to Dr. Christiano, such patients gain little benefit from existing hair-loss medications, which tend to slow the rate of hair loss but usually do not stimulate robust new hair growth.
“Dermal papilla cells give rise to hair follicles, and the notion of cloning hair follicles using inductive dermal papilla cells has been around for 40 years or so,” said co-study leader Colin Jahoda, PhD, professor of stem cell sciences at Durham University, England, and co-director of North East England Stem Cell Institute, who is one of the early founders of the field. “However, once the dermal papilla cells are put into conventional, two-dimensional tissue culture, they revert to basic skin cells and lose their ability to produce hair follicles. So we were faced with a Catch-22: how to expand a sufficiently large number of cells for hair regeneration while retaining their inductive properties.”
The researchers found a clue to overcoming this barrier in their observations of rodent hair. Rodent papillae can be easily harvested, expanded, and successfully transplanted back into rodent skin, a method pioneered by Dr. Jahoda several years ago. The main reason that rodent hair is readily transplantable, the researchers suspected, is that their dermal papillae (unlike human papillae) tend to spontaneously aggregate, or form clumps, in tissue culture. The team reasoned that these aggregations must create their own extracellular environment, which allows the papillae to interact and release signals that ultimately reprogram the recipient skin to grow new follicles.
“This suggested that if we cultured human papillae in such a way as to encourage them to aggregate the way rodent cells do spontaneously, it could create the conditions needed to induce hair growth in human skin,” said first author Claire A. Higgins, PhD, associate research scientist.
To test their hypothesis, the researchers harvested dermal papillae from seven human donors and cloned the cells in tissue culture; no additional growth factors were added to the cultures. After a few days, the cultured papillae were transplanted between the dermis and epidermis of human skin that had been grafted onto the backs of mice. In five of the seven tests, the transplants resulted in new hair growth that lasted at least six weeks. DNA analysis confirmed that the new hair follicles were human and genetically matched the donors.
“This approach has the potential to transform the medical treatment of hair loss,” said Dr. Christiano. “Current hair-loss medications tend to slow the loss of hair follicles or potentially stimulate the growth of existing hairs, but they do not create new hair follicles. Neither do conventional hair transplants, which relocate a set number of hairs from the back of the scalp to the front. Our method, in contrast, has the potential to actually grow new follicles using a patient’s own cells. This could greatly expand the utility of hair restoration surgery to women and to younger patients – now it is largely restricted to the treatment of male-pattern baldness in patients with stable disease.”
More work needs to be done before the method can be tested in humans, according to the researchers. “We need to establish the origins of the critical intrinsic properties of the newly induced hairs, such as their hair cycle kinetics, color, angle, positioning, and texture” said Dr. Jahoda. “We also need to establish the role of the host epidermal cells that the dermal papilla cells interact with, to make the new structures.” The team is optimistic that clinical trials could begin in the near future. “We also think that this study is an important step toward the goal of creating a replacement skin that contains hair follicles for use with, for example, burn patients,” said Dr Jahoda.
The researchers used gene expression analyses to determine that the three-dimensional cultures restored 22 percent of the gene expression seen in normal hair follicles. “That’s less than we expected, but it was sufficient for inducing the growth of new hair follicles,” said Dr. Christiano.
In addition, using methods for the analysis of regulatory networks developed by the Califano lab in the Center for Computational Biology and Bioinformatics, Department of Systems Biology, the researchers identified a number of transcription factors (gene regulators) that have the potential to mimic the environmental signals that trigger papillae to induce new hair growth. This information could help researchers develop ways to restore the expression of more genes involved in hair growth and to increase the efficiency of the induction.
The paper is titled, “Microenvironmental reprogramming by three-dimensional culture enables dermal papilla cells to induce de novo human hair follicle growth.” The other contributors are James C. Chen and Jane E. Cerise, both at CUMC.
The study was supported by a Science of Human Appearance Career Development Award from the Dermatology Foundation and by grants from the Medical Research Council of the UK, the Empire State Development’s Division of Science, Technology and Innovation (NYSTAR), New York Stem Cell Science (NYSTEM), and the Biotechnology and Biological Sciences Research Council in the UK (BBSRC), as well as earlier support from the Steven and Michele Kirsch Foundation. Dr. Christiano is a member of the Columbia Stem Cell Initiative. The authors declare no financial or other conflicts of interests.
About Columbia University Medical Center
Columbia University Medical Center provides international leadership in basic, preclinical, and clinical research; medical and health sciences education; and patient care. The medical center trains future leaders and includes the dedicated work of many physicians, scientists, public health professionals, dentists, and nurses at the College of Physicians and Surgeons, the Mailman School of Public Health, the College of Dental Medicine, the School of Nursing, the biomedical departments of the Graduate School of Arts and Sciences, and allied research centers and institutions. Columbia University Medical Center is home to the largest medical research enterprise in New York City and State and one of the largest faculty medical practices in the Northeast. For more information, visit cumc.columbia.edu or columbiadoctors.org.
About Durham University
Durham University is a world top 100 university with a global reputation and performance in research and education.
The most recent UK league tables place Durham in the top echelon of British universities academically.
Durham is ranked fifth in the UK in the Complete University Guide 2014 and sixth in the Times and Sunday Times Good University Guide 2014; it is in the world top 25 for the employability of its students by blue-chip companies world-wide (QS World University Rankings 2013/14) and in the global top 30 for Arts and Humanities (the World University Rankings 2013/14).
We are a residential Collegiate University: England’s third-oldest university and at our heart is a medieval UNESCO World Heritage Site, of which we are joint custodians with Durham Cathedral. Durham is a member of the Russell Group of leading research-intensive UK universities.http://www.durham.ac.uk