Bamboo bike recharges mobile devices, external batteries by peddling

Bambootec consortium from Yucatán, state in the south of Mexico, designed a bamboo bicycle that transforms the kinetic energy generated by pedaling into a source of electricity that has the ability to simultaneously recharge mobile devices, smartphone's external battery and a navigation dashboard located on the handlebars which measures the distance and time, and also has bluetooth connection.

The energy transfer is possible thanks to a converter, which is composed of a circuit that starts on the rim, captures the kinetic energy and converts it into electricity. After passing through the core of the system located under the seat, which purpose is to regulate the voltage generated and prevent discharges, said Cristina Espinosa López, founder of Bambootec.

When pedaling, the cyclist produces energy that is transformed into electricity. However, if done irregularly, by either unexpected racing or braking, the load rises and falls; to solve this problem a regulator was added to the converter to administer the charge evenly.

In addition to the power converter system, the bicycle has a frame (vertices and edges) assembled with bamboo sticks connected by a special resin. The aim was to replace metal parts for this natural material in order to provide the vehicle with greater resistance (supports 120 kilos), also making it lighter and less prone to heat, explained the founder of Bambootec.

Once the converter regulates the energy charge, this is transmitted through three channels of power, which are cables with an usb output. One is connected to the navigation screen located on the handlebars of the bicycle, which indicates the number of kilometers and time passed, and provides the option to establish a connection via Bluetooth to link to a smartphone.

The other terminal of the power converter recharges any mobile device, while the third one is exclusive to recharge smartphone's external batteries. It is important to highlight that the energy generated by the bicycle (over 10 volts) is enough to feed the three tracks simultaneously, López Espinosa specified.

Currently, bicycle testing have shown that the charge capacity for the devices is of one percent per minute. It is required to optimize the system in order to accelerate the charging process.

The team integrated by Espinosa Lopez, Alfonso Xool Moo, Luis Villar del Maso and Edson Ochoa Herrera has as a main goal to create the necessary machinery to scale the product and mass produce it; because of this the company participated in the Cleantech Challenge Mexico, a contest that promotes the development of green enterprises. 

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IPCC report: Climate change threatens irreversible and dangerous impacts, but options exist to limit its effects

A new report from the IPCC says that climate change -- if left unchecked -- will increase the likelihood of severe, pervasive and irreversible impacts for people and ecosystems.

Human influence on the climate system is clear and growing, with impacts observed on all continents. If left unchecked, climate change will increase the likelihood of severe, pervasive and irreversible impacts for people and ecosystems. However, options are available to adapt to climate change and implementing stringent mitigations activities can ensure that the impacts of climate change remain within a manageable range, creating a brighter and more sustainable future.

These are among the key findings of the Synthesis Report released by the Intergovernmental Panel on Climate Change (IPCC) on Nov. 2, 2014. The Synthesis Report distils and integrates the findings of the IPCC Fifth Assessment Report produced by over 800 scientists and released over the past 13 months -- the most comprehensive assessment of climate change ever undertaken.

"We have the means to limit climate change," said R. K. Pachauri, Chair of the IPCC. "The solutions are many and allow for continued economic and human development. All we need is the will to change, which we trust will be motivated by knowledge and an understanding of the science of climate change."

The Synthesis Report confirms that climate change is being registered around the world and warming of the climate system is unequivocal. Since the 1950s many of the observed changes are unprecedented over decades to millennia. "Our assessment finds that the atmosphere and oceans have warmed, the amount of snow and ice has diminished, sea level has risen and the concentration of carbon dioxide has increased to a level unprecedented in at least the last 800,000 years," said Thomas Stocker, Co-Chair of IPCC Working Group I.

The report expresses with greater certainty than in previous assessments the fact that emissions of greenhouse gases and other anthropogenic drivers have been the dominant cause of observed warming since the mid-20th century.

The impacts of climate change have already been felt in recent decades on all continents and across the oceans.

The more human activity disrupts the climate, the greater the risks. Continued emissions of greenhouse gases will cause further warming and long-lasting changes in all components of the climate system, increasing the likelihood of widespread and profound impacts affecting all levels of society and the natural world, the report finds.

The Synthesis Report makes a clear case that many risks constitute particular challenges for the least developed countries and vulnerable communities, given their limited ability to cope. People who are socially, economically, culturally, politically, institutionally, or otherwise marginalized are especially vulnerable to climate change.

Indeed, limiting the effects of climate change raise issues of equity, justice, and fairness and is necessary to achieve sustainable development and poverty eradication. "Many of those most vulnerable to climate change have contributed and contribute little to greenhouse gas emissions," Pachauri said. "Addressing climate change will not be possible if individual agents advance their own interests independently; it can only be achieved through cooperative responses, including international cooperation."

"Adaptation can play a key role in decreasing these risks," said Vicente Barros, Co-Chair of IPCC Working Group II. "Adaptation is so important because it can be integrated with the pursuit of development, and can help prepare for the risks to which we are already committed by past emissions and existing infrastructure."

But adaptation alone is not enough. Substantial and sustained reductions of greenhouse gas emissions are at the core of limiting the risks of climate change. And since mitigation reduces the rate as well as the magnitude of warming, it also increases the time available for adaptation to a particular level of climate change, potentially by several decades.

There are multiple mitigation pathways to achieve the substantial emissions reductions over the next few decades necessary to limit, with a greater than 66% chance, the warming to 2 degrees C -- the goal set by governments. However, delaying additional mitigation to 2030 will substantially increase the technological, economic, social and institutional challenges associated with limiting the warming over the 21st century to below 2ºC relative to pre-industrial levels, the report finds.

"It is technically feasible to transition to a low-carbon economy," said Youba Sokona, Co-Chair of IPCC Working Group III. "But what is lacking are appropriate policies and institutions. The longer we wait to take action, the more it will cost to adapt and mitigate climate change." The Synthesis Report finds that mitigation cost estimates vary, but that global economic growth would not be strongly affected. In business-as-usual scenarios, consumption -- a proxy for economic growth -- grows by 1.6 to 3 percent per year over the 21st century. Ambitious mitigation would reduce this by about 0.06 percentage points. "Compared to the imminent risk of irreversible climate change impacts, the risks of mitigation are manageable" said Sokona.

These economic estimates of mitigation costs do not account for the benefits of reduced climate change, nor do they account for the numerous co-benefits associated with human health, livelihoods, and development. "The scientific case for prioritizing action on climate change is clearer than ever," Pachauri said. "We have little time before the window of opportunity to stay within 2ºC of warming closes. To keep a good chance of staying below 2ºC, and at manageable costs, our emissions should drop by 40 to 70 percent globally between 2010 and 2050, falling to zero or below by 2100. We have that opportunity, and the choice is in our hands."

Comprehensive assessment

The Synthesis Report, written under the leadership of IPCC Chair R.K. Pachauri, forms the capstone of the IPCC Fifth Assessment Report. The first three volumes, based on outlines approved by the IPCC's 195 member governments in October 2009, were released over the past fourteen months: The Physical Science Basis in September 2013, Impacts, Adaptation and Vulnerability, in March 2014 and Mitigation of Climate Change in April 2014.

IPCC reports draw on the many years of work by the scientific community investigating climate change. More than 830 coordinating lead authors, lead authors and review editors from over 80 countries and covering a range of scientific, technical and socio-economic views and expertise, produced the three working group contributions, supported by over 1000 contributing authors and drawing on the insights of over 2,000 expert reviewers in a process of repeated review and revision. The authors assessed more than 30,000 scientific papers to develop the Fifth Assessment Report. About 60 authors and editors drawn from the IPCC Bureau and from Working Group author teams have been involved in the writing of the Synthesis Report. Their work was made possible by the contributions and dedication of the Synthesis Report Technical Support Unit.

"I would like to thank the hundreds of experts from the world's scientific community who have given freely of their time and expertise to produce the most comprehensive assessment of climate change yet undertaken," said Pachauri. "I hope this report will serve the needs of the world's governments and provide the scientific basis to negotiators as they work towards a new global climate agreement."

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Plant genetic advance could lead to more efficient conversion of plant biomass to biofuels

Plant geneticists including Sam Hazen at the University of Massachusetts Amherst and Siobhan Brady at the University of California, Davis, have sorted out the gene regulatory networks that control cell wall thickening by the synthesis of the three polymers, cellulose, hemicellulose and lignin..

The authors say that the most rigid of the polymers, lignin, represents "a major impediment" to extracting sugars from plant biomass that can be used to make biofuels. Their genetic advance is expected to "serve as a foundation for understanding the regulation of a complex, integral plant component" and as a map for how future researchers might manipulate the polymer-forming processes to improve the efficiency of biofuel production.

The three key components, found in plant tissues known as xylem, provide plants with mechanical strength and waterproof cells that transport water. Working in the model plant Arabidopsis thaliana, Hazen, Brady and colleagues explored how a large number of interconnected transcription factors regulate xylem and cell wall thickening. Results appeared in an early online edition Dec. 24 in Nature.

An invited commentary in the journal on the significance of this discovery points out that "understanding how the relative proportions of these biopolymers are controlled in plant tissue would open up opportunities to redesign plants for biofuel use."Hazen, Brady and colleagues'study identified hundreds of new regulators and offers "considerable insight," the authors say, "into the developmental regulation of xylem cell differentiation."

Specifically, using a systems approach to identify protein-DNA interactions, they screened more than 460 transcription factors expressed in root xylem to explore their ability to bind the promoters of about 50 genes known to be involved in processes that produce cell-wall components. Hazen says, "This revealed a highly interconnected network of more than 240 genes and more than 600 protein-DNA interactions that we had not known about before."

They also found that each cell-wall gene in the xylem regulatory network is bound by an average of five different transcription factors from 35 distinct families of regulatory proteins. Further, many of the transcription factors form a surprisingly large number of feed-forward loops that co-regulate target genes.

In other words, rather than a series of on-off switches that leads to an ultimate action like making cellulose, most of the proteins including regulators of cell cycle and differentiation bind directly to cellulose genes and to other transcription regulators. This gives plants a huge number of possible combinations for responding and adapting to environmental stress such as salt or drought, the authors point out.

While this study could identify interactive nodes, the techniques used were not able to let the authors determine exactly what types of feed forward loops are present in the xylem regulatory network. However, the work offers a framework for future research that should allow researchers to identify ways to manipulate this network and engineer energy crops for biofuel production.

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Quantum channel made of light

A point contact through which neutral, ultracold atoms flow. According to the laws of quantum physics, conductivity can only change in discrete steps.

Two vessels filled with gas and connected by a channel -- this is the basic setting for the experiments carried out by the physicists at the ETH Institute for Quantum Electronics. As one vessel contains more gas than the other, particles flow through the channel from one side to the other. "The question now is how the conductivity changes as we gradually make the channel narrower," says physics professor Tilman Esslinger. Initially, the conductivity decreases smoothly. However, at some point an amazing phenomenon appears: the conductivity does not change continuously anymore, but in steps, and the size of the steps is determined by a fundamental entity known as the Planck constant. "This is an immediate consequence of quantum physics," explains Esslinger.

The phenomenon has been observed before, but only in electronic systems, such as in quantum point contacts in specific semiconductor structures. "We have now observed for the first time quantisation of conductivity in neutral matter; that is, for particles that are not charged," says Esslinger. "This experiment is certainly something for the quantum-physics textbooks."

This basic-research project, which is supported by the Swiss National Science Foundation (SNF) and the European Union, might be of relevance for the design and construction of the next generation of electronic devices, as it enables the future study of effects that currently cannot be explored with electronic systems.

Cooling to almost absolute zero

The group led by Tilman Esslinger works with ultracold atoms. In the experiment described by the researchers in the current issue of the journal Nature, they used a gas consisting of lithium atoms at a temperature of merely 35 billionths of a degree above absolute zero. "Cooling is the main focus of our work in the lab," says Dr Jean-Philippe Brantut, SNF Ambizione Fellow at the Institute for Quantum Electronics. "99 percent of our equipment, which we developed in house, serves that purpose." Cooled to such low temperatures, the lithium atoms behave similarly to electrons in a solid-state material, even if -- in contrast to electrons -- the atoms are not charged.

The centrepieces of the complex experimental setup are a high-vacuum glass cell and two ultra-high-resolution microscopes. The lithium gas sits in the cell between the microscopes, in a cigar-shaped cloud with a diameter of approximately 300 micrometres. A laser beam divides this cloud into two reservoirs, connected by a narrow two-dimensional channel. A second laser beam passes through a lithographically produced mask and then through a projection system made of a lens and one of the microscopes. In this way, the pattern defined on the mask is reduced to the size of the channel. As a result, a quantum point contact with a width of just one micrometre is created, as can be validated using the other microscope.

Microscopic flow requires a stable system

The channel structure is sufficiently narrow that the laws of quantum mechanics come into play. This means that for atoms flowing through the channel, the conductivity should change not continuously but in steps, whose size are given by Planck's quantum of action, which is a fundamental constant of nature. This behaviour is precisely what the research group has observed. Ten atoms are in the channel at a time, says Brantut. To make the microscopic flow visible, the channel had to be kept open until 1,000 or so atoms have passed through it. This took some 1.5 seconds, which is a rather long time for an experiment of this type. "The experiment can only work if the atoms are very stable -- that is, extremely cold -- and nothing else changes," explains the physicist.

The atoms transverse the experimental setup like small bullets, without being thrown off course by collisions. The physicists therefore refer to this as a ballistic system. The electronics industry is looking to develop in the future ballistic transistors, in which electrical resistance is extremely low. The experiments involving neutral atoms and laser light might contribute to these developments, as they enable scientists to systematically study theoretical models and compare results directly, which often is not possible with electronic systems, due to the current inability to produce suitable samples. "Until now, we have been carrying out measurements based on predictions from theoretical models," says Brantut. "Now we are venturing into uncharted territory."

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NASA finds good news on forests and carbon dioxide

A new NASA study suggests that tropical forests absorb more atmospheric carbon dioxide than is absorbed by forests in Alaska, Canada and Siberia.

A new NASA-led study shows that tropical forests may be absorbing far more carbon dioxide than many scientists thought, in response to rising atmospheric levels of the greenhouse gas. The study estimates that tropical forests absorb 1.4 billion metric tons of carbon dioxide out of a total global absorption of 2.5 billion -- more than is absorbed by forests in Canada, Siberia and other northern regions, called boreal forests.

"This is good news, because uptake in boreal forests is already slowing, while tropical forests may continue to take up carbon for many years," said David Schimel of NASA's Jet Propulsion Laboratory, Pasadena, California. Schimel is lead author of a paper on the new research, appearing online in the Proceedings of National Academy of Sciences.

Forests and other land vegetation currently remove up to 30 percent of human carbon dioxide emissions from the atmosphere during photosynthesis. If the rate of absorption were to slow down, the rate of global warming would speed up in return.

The new study is the first to devise a way to make apples-to-apples comparisons of carbon dioxide estimates from many sources at different scales: computer models of ecosystem processes, atmospheric models run backward in time to deduce the sources of today's concentrations (called inverse models), satellite images, data from experimental forest plots and more. The researchers reconciled all types of analyses and assessed the accuracy of the results based on how well they reproduced independent, ground-based measurements. They obtained their new estimate of the tropical carbon absorption from the models they determined to be the most trusted and verified.

"Until our analysis, no one had successfully completed a global reconciliation of information about carbon dioxide effects from the atmospheric, forestry and modeling communities," said co-author Joshua Fisher of JPL. "It is incredible that all these different types of independent data sources start to converge on an answer."

The question of which type of forest is the bigger carbon absorber "is not just an accounting curiosity," said co-author Britton Stephens of the National Center for Atmospheric Research, Boulder, Colorado. "It has big implications for our understanding of whether global terrestrial ecosystems might continue to offset our carbon dioxide emissions or might begin to exacerbate climate change."

As human-caused emissions add more carbon dioxide to the atmosphere, forests worldwide are using it to grow faster, reducing the amount that stays airborne. This effect is called carbon fertilization. "All else being equal, the effect is stronger at higher temperatures, meaning it will be higher in the tropics than in the boreal forests," Schimel said.

But climate change also decreases water availability in some regions and makes Earth warmer, leading to more frequent and larger wildfires. In the tropics, humans compound the problem by burning wood during deforestation. Fires don't just stop carbon absorption by killing trees, they also spew huge amounts of carbon into the atmosphere as the wood burns.

For about 25 years, most computer climate models have been showing that mid-latitude forests in the Northern Hemisphere absorb more carbon than tropical forests. That result was initially based on the then-current understanding of global air flows and limited data suggesting that deforestation was causing tropical forests to release more carbon dioxide than they were absorbing.

In the mid-2000s, Stephens used measurements of carbon dioxide made from aircraft to show that many climate models were not correctly representing flows of carbon above ground level. Models that matched the aircraft measurements better showed more carbon absorption in the tropical forests. However, there were still not enough global data sets to validate the idea of a large tropical-forest absorption. Schimel said that their new study took advantage of a great deal of work other scientists have done since Stephens' paper to pull together national and regional data of various kinds into robust, global data sets.

Schimel noted that their paper reconciles results at every scale from the pores of a single leaf, where photosynthesis takes place, to the whole Earth, as air moves carbon dioxide around the globe. "What we've had up till this paper was a theory of carbon dioxide fertilization based on phenomena at the microscopic scale and observations at the global scale that appeared to contradict those phenomena. Here, at least, is a hypothesis that provides a consistent explanation that includes both how we know photosynthesis works and what's happening at the planetary scale."

NASA monitors Earth's vital signs from land, air and space with a fleet of satellites and ambitious airborne and ground-based observation campaigns. NASA develops new ways to observe and study Earth's interconnected natural systems with long-term data records and computer analysis tools to better see how our planet is changing. The agency shares this unique knowledge with the global community and works with institutions in the United States and around the world that contribute to understanding and protecting our home planet.

For more information about NASA's Earth science activities in the last year, visit: http://www nasa gov/ earthrightnow

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Ten exciting astronomy stories from 2014

Messier 82, seen in radio frequencies by the Karl G. Jansky Very Large Array.

Looking back at the science news released by the National Radio Astronomy Observatory (NRAO) in 2014, the staff scientists at NRAO selected what they believe are the top 10 stories based on both scientific impact and public interest.

"These 'top ten' are just a small sampling of the myriad ways in which the state-of-the-art NRAO facilities are enabling forefront research by the astronomical community," said NRAO Chief Scientist Chris Carilli. "Using new telescopes, instrumentation, and techniques, facilitated by the NRAO, U.S. and international astronomers are addressing the most pressing problems in planet, star, and galaxy formation, fundamental physics and cosmology, and astrochemistry and biology, while finding some real surprises along the way!"

#10 Image Release: Starbursting in the Galaxy M82

A new radio image, made with the Karl G. Jansky Very Large Array (VLA), reveals fresh information about the central 5200 light-years of the starbursting galaxy M82. The radio emission seen in the image is produced by ionized gas and by fast-moving electrons interacting with the interstellar magnetic field. The bright dots are a mix of star-forming regions and supernova remnants, the debris from stellar explosions; analysis of the VLA data tells scientists which of these are which. Scientists also are studying the faint, wispy features, many of which were previously unseen, to investigate their relationship with this galaxy's starburst-driven superwind.

#9 Remarkable White Dwarf Star Possibly Coldest, Dimmest Ever Detected

A team of astronomers has identified possibly the coldest, faintest white dwarf star ever detected. This ancient stellar remnant is so cool that its carbon has crystallized, forming -- in effect -- an Earth-size diamond in space. The researchers found this stellar gem using the National Radio Astronomy Observatory's (NRAO) Green Bank Telescope (GBT) and Very Long Baseline Array (VLBA), as well as other observatories. Other such stars have been identified and they are theoretically not that rare, but with a low intrinsic brightness, they can be deucedly difficult to detect. Its fortuitous location in a binary system with a neutron star enabled the team to identify this one.

#8 Newly Identified Galactic Supercluster Is Home to the Milky Way

Astronomers using the National Science Foundation's Green Bank Telescope (GBT) -- among other telescopes -- have determined that our own Milky Way galaxy is part of a newly identified ginormous supercluster of galaxies, which they have dubbed "Laniakea," which means "immense heaven" in Hawaiian. This discovery clarifies the boundaries of our galactic neighborhood and establishes previously unrecognized linkages among various galaxy clusters in the local Universe. By using the GBT and other radio telescopes to map the velocities of galaxies throughout our local Universe, the team was able to define the region of space where each supercluster dominates.

#7 Planet-forming Lifeline Discovered in a Binary Star System

Scientists using the Atacama Large Millimeter/submillimeter Array (ALMA) have detected a streamer of dust and gas flowing from a massive outer disk toward the inner reaches of a binary star system known as GG Tau-A. This newly discovered feature may be responsible for sustaining a second, smaller disk of planet-forming material that otherwise would have disappeared long ago. Like a wheel in a wheel, GG Tau-A contains a large, outer disk encircling the entire system as well as an inner disk around the main central star. While observing these structures with ALMA, the team made the exciting discovery of gas clumps in the region between the two disks. The new observations suggest that material is being transferred from the outer disk to the inner disk, creating a sustaining lifeline between the two.

#6 Orion Rocks! Pebble-size Particles May Kick Start Planet Formation

Astronomers using the National Science Foundation's (NSF) Green Bank Telescope (GBT) have discovered that filaments of star-forming gas near the Orion Nebula may be brimming with pebble-size particles -- planetary building blocks 100 to 1,000 times larger than the dust grains typically found around protostars. If confirmed, these dense ribbons of rocky material may well represent a new, mid-size class of interstellar particles that could help jump-start planet formation. Though incredibly small compared to even the most modest of asteroids, dust grains on the order of a few millimeters to a centimeter are incredibly large for such young star-forming regions.

#5 Swarms of Pluto-size Objects Kick Up Dust around Adolescent Sun-Like Star

Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) may have detected the dusty hallmarks of an entire family of Pluto-size objects swarming around an adolescent version of our own Sun. By making detailed observations of the protoplanetary disk surrounding the star known as HD 107146, the astronomers detected an unexpected increase in the concentration of millimeter-size dust grains in the disk's outer reaches. This surprising increase, which begins remarkably far -- about 13 billion kilometers -- from the host star, may be the result of Pluto-size planetesimals stirring up the region, causing smaller objects to collide and blast themselves apart.

#4 Pulsar in a Stellar Triple System Makes Unique Gravitational Laboratory

Astronomers using the National Science Foundation's Green Bank Telescope (GBT) have discovered a unique stellar system of two white dwarf stars and a superdense neutron star, all packed within a space smaller than Earth's orbit around the Sun. The closeness of the stars, combined with their nature, has allowed the scientists to make the best measurements yet of the complex gravitational interactions in such a system. In addition, detailed studies of this system may provide a key clue for resolving one of the principal outstanding problems of fundamental physics -- the true nature of gravity.

#3 New Radar Images Uncover Remarkable Features below the Surface of the Moon: Sea of Serenity and Aristillus Crater

New images of Earth's Moon reveal more than can be seen with the naked eye, thanks to the combined efforts of the two largest radio telescopes of their kind -- the National Radio Astronomy Observatory's Green Bank Telescope (GBT) in West Virginia and the Arecibo Observatory in Puerto Rico. To make these images, radar signals beamed from Arecibo's powerful transmitter penetrated far below the Moon's dusty surface. The signals then rebounded back and were picked up by the sensitive receivers on the GBT. This observing technique, known as bistatic radar, has been used to study many objects in our Solar System, including asteroids and other planets.

#2 Radio Telescopes Settle Controversy over Distance to Pleiades

Astronomers have used a worldwide network of radio telescopes to resolve a controversy over the distance to a famous star cluster -- a controversy that posed a potential challenge to scientists' basic understanding of how stars form and evolve. The new work shows that the measurement made by a cosmic-mapping research satellite was wrong. The result of their work is a distance to the Pleiades of 443 light-years, accurate, the astronomers said, to within one percent. This is the most accurate and precise measurement yet made of the Pleiades distance.

#1 Birth of Planets Revealed in Astonishing Detail in ALMA's 'Best Image Ever'

Astronomers have captured the best image ever of planet formation around an infant star as part of the testing and verification process for the Atacama Large Millimeter/submillimeter Array's (ALMA) new high-resolution capabilities. This revolutionary new image reveals in astonishing detail the planet-forming disk surrounding HL Tau, a Sun-like star located approximately 450 light-years from Earth in the constellation Taurus. ALMA uncovered never-before-seen features in this system, including multiple concentric rings separated by clearly defined gaps. These structures suggest that planet formation is already well underway around this remarkably young star.

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Patient stem cells used to make dementia-in-a-dish; help identify new treatment strategy

Induced pluripotent stem cells (iPSCs) derived from patients with frontotemporal dementia were genetically corrected and converted to cortical neurons. The green staining indicates the cortical marker CTIP2, the red stain is the neuronal marker TUJ1, and the blue stains the nuclei of the cells.

Belgian researchers have identified a new strategy for treating an inherited form of dementia after attempting to turn stem cells derived from patients into the neurons most affected by the disease. In patient-derived stem cells carrying a mutation predisposing them to frontotemporal dementia, which accounts for about half of dementia cases before the age of 60, the scientists found a targetable defect that prevents normal neurodevelopment. These stem cells partially return to normal when the defect is corrected.

The study appears in the December 31st issue of Stem Cell Reports, the official journal of the International Society of Stem Cell Research published by Cell Press.

"Use of induced pluripotent stem cell (iPSC) technology"--which involves taking skin cells from patients and reprogramming them into embryonic-like stem cells capable of turning into other specific cell types relevant for studying a particular disease--"makes it possible to model dementias that affect people later in life," says senior study author Catherine Verfaillie of KU Leuven.

Frontotemporal disorders are the result of damage to neurons in parts of the brain called the frontal and temporal lobes, gradually leading to behavioral symptoms or language and emotional disorders. Mutations in a gene called progranulin (GRN) are commonly associated with frontotemporal dementia, but GRN mutations in mice do not mimic all the features of the human disorder, which has limited progress in the development of effective treatments.

"iPSC models can now be used to better understand dementia, and in particular frontotemporal dementia, and might lead to the development of drugs that can curtail or slow down the degeneration of cortical neurons," Verfaillie says.

Verfaillie and Philip Van Damme of the Leuven Research Institute for Neuroscience and Disease explore this approach in the Stem Cell Reports study by creating iPSCs from three patients carrying a GRN mutation. These immature cells were impaired at turning into mature, specialized cells called cortical neurons--the most affected cell type in frontotemporal dementia.

One of the top defective pathways in the iPSCs was the Wnt signaling pathway, which plays an important role in neuronal development. However, genetic correction or treatment with a compound that inhibits the Wnt signaling pathway restored the ability of the iPSCs to turn into cortical neurons. Taken together, the findings demonstrate that the GRN mutation causes the defect in cortical neuron formation by altering the Wnt signaling pathway.

"Our findings suggest that signaling events required for neurodevelopment may also play major roles in neurodegeneration," Van Damme says. "Targeting such pathways, as for instance the Wnt pathway presented in this study, may result in the creation of novel therapeutic approaches for frontotemporal dementia."

The researchers will now work to better understand what goes wrong in GRN-mutated cells, as well as identify precise molecular targets that could then be used for drug screens.

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Trial confirms Ebola vaccine candidate safe, equally immunogenic in Africa

Two experimental DNA vaccines to prevent Ebola virus and the closely related Marburg virus are safe, and generated a similar immune response in healthy Ugandan adults as reported in healthy US adults earlier this year. The findings, from the first trial of filovirus vaccines in Africa, are published in The Lancet.

"This is the first study to show comparable safety and immune response of an experimental Ebola vaccine in an African population," says lead author Dr Julie Ledgerwood from the National Institutes of Allergy and Infectious Diseases (NIAID) at the National Institutes of Health, USA. "This is particularly encouraging because those at greatest risk of Ebola live primarily in Africa, and diminished vaccine protection in African populations has been seen for other diseases."

Scientists from the NIAID developed the DNA vaccines that code for Ebola virus proteins from the Zaire and Sudan strains and the Marburg virus protein. The vaccines contain the construction plans for the proteins on the outer surface of the virus. Immune responses against these proteins have shown to be highly protective in non-human primate models.

In this phase 1 trial, the Makerere University Walter Reed Program enrolled 108 healthy adults aged between 18 and 50 from Kampala, Uganda between November, 2009 and April, 2010. Each volunteer was randomly assigned to receive an intramuscular injection of either the Ebola vaccine (30 volunteers), Marburg vaccine (30), both vaccines (30), or placebo (18) at the start of the study, and again 4 weeks and 8 weeks later.

The vaccines given separately and together were safe and stimulated an immune response in the form of neutralising antibodies and T-cells against the virus proteins. Four weeks after the third injection, just over half of the volunteers (57%; 17 of 30) had an antibody response to the Ebola Zaire protein as did 14 of 30 participants who received both the Ebola and Marburg vaccines. However, the antibodies were not long-lasting and returned to undetectable levels within 11 months of vaccination.

Both DNA vaccines were well tolerated in Ugandan adults with similar numbers of local and systemic reactions reported in all groups. Only one serious adverse event (neutropenia; low white blood cell count) was reported in a Marburg vaccine only recipient, but was not thought to be vaccine related.

According to Dr Ledgerwood, "These findings have already formed the basis of a more potent vaccine, delivered using a harmless chimpanzee cold virus, which is undergoing trials in the USA, UK, Mali, and Uganda in response to the ongoing Ebola virus outbreak."

Writing in a linked Comment, Dr Saranya Sridhar from the Jenner Institute at the University of Oxford in the UK says, "[This] study deserves to be the focal point around which the broader question of vaccine development, particularly for Africa, must be addressed. With the uncharitable benefit of hindsight in view of the evolving 2014 Ebola outbreak, we must ask ourselves whether a filovirus vaccine should have been in more advanced clinical development. The international response to the present Ebola outbreak is an exemplar of the speed and purpose with which clinical vaccine development can progress and has set the benchmark against which future vaccine development must be judged. This study is the first step on the aspirational road towards the deployment of filovirus vaccines in Africa and must serve to shake the metaphorical cobwebs that can stall our advance towards this destination."

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Dawn spacecraft begins approach to dwarf planet Ceres

This artist's concept shows NASA's Dawn spacecraft heading toward the dwarf planet Ceres.

NASA's Dawn spacecraft has entered an approach phase in which it will continue to close in on Ceres, a Texas-sized dwarf planet never before visited by a spacecraft. Dawn launched in 2007 and is scheduled to enter Ceres orbit in March 2015.

Dawn recently emerged from solar conjunction, in which the spacecraft is on the opposite side of the sun, limiting communication with antennas on Earth. Now that Dawn can reliably communicate with Earth again, mission controllers have programmed the maneuvers necessary for the next stage of the rendezvous, which they label the Ceres approach phase. Dawn is currently 400,000 miles (640,000 kilometers) from Ceres, approaching it at around 450 miles per hour (725 kilometers per hour).

The spacecraft's arrival at Ceres will mark the first time that a spacecraft has ever orbited two solar system targets. Dawn previously explored the protoplanet Vesta for 14 months, from 2011 to 2012, capturing detailed images and data about that body.

"Ceres is almost a complete mystery to us," said Christopher Russell, principal investigator for the Dawn mission, based at the University of California, Los Angeles. "Ceres, unlike Vesta, has no meteorites linked to it to help reveal its secrets. All we can predict with confidence is that we will be surprised."

The two planetary bodies are thought to be different in a few important ways. Ceres may have formed later than Vesta, and with a cooler interior. Current evidence suggests that Vesta only retained a small amount of water because it formed earlier, when radioactive material was more abundant, which would have produced more heat. Ceres, in contrast, has a thick ice mantle and may even have an ocean beneath its icy crust.

Ceres, with an average diameter of 590 miles (950 kilometers), is also the largest body in the asteroid belt, the strip of solar system real estate between Mars and Jupiter. By comparison, Vesta has an average diameter of 326 miles (525 kilometers), and is the second most massive body in the belt.

The spacecraft uses ion propulsion to traverse space far more efficiently than if it used chemical propulsion. In an ion propulsion engine, an electrical charge is applied to xenon gas, and charged metal grids accelerate the xenon particles out of the thruster. These particles push back on the thruster as they exit, creating a reaction force that propels the spacecraft. Dawn has now completed five years of accumulated thrust time, far more than any other spacecraft.

"Orbiting both Vesta and Ceres would be truly impossible with conventional propulsion. Thanks to ion propulsion, we're about to make history as the first spaceship ever to orbit two unexplored alien worlds," said Marc Rayman, Dawn's chief engineer and mission director, based at NASA's Jet Propulsion Laboratory in Pasadena, California.

The next couple of months promise continually improving views of Ceres, prior to Dawn's arrival. By the end of January, the spacecraft's images and other data will be the best ever taken of the dwarf planet.

The Dawn mission to Vesta and Ceres is managed by JPL, a division of the California Institute of Technology in Pasadena, for NASA's Science Mission Directorate, Washington. UCLA is responsible for overall Dawn mission science.

More information about Dawn: http://dawn jpl nasa.gov

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Simulation of universe with realistic galaxies

An international team of astronomers, based at the Universities of Leiden in the Netherlands and Durham in the UK and, led by professor Joop Schaye (Leiden University), developed a simulation of the universe in which realistic galaxies are created; their mass, size and age are similar to those of observed galaxies. Their similarity is caused by the simulation of strong galactic winds -- gas winds that are blown from galaxies.

The simulations took several months to run at the "Cosmology Machine" in Durham and at "Curie" in Paris, among the largest computers used for scientific research in the U.K. and France, respectively. Astronomers can now use the results to study the development of galaxies from almost 14 billion years ago until now. The results will be published in Monthly Notices of the Royal Astronomical Society on 1 January.

For years, astronomers have studied the formation of galaxies using computer simulations, but with limited success. The galaxies that formed in previous simulations were often too massive, too small, too old and too spherical.

The galaxies formed in the EAGLE-simulation (Evolution and Assembly of GaLaxies and their Environments) are a much closer reflection of real galaxies thanks to the strong galactic winds, which blow away the gas supply needed for the formation of stars. EAGLE's galaxies are lighter and younger because fewer stars form and they form later. In the EAGLE simulation these galactic winds -- which are powered by stars, supernova explosions and supermassive black holes -- are stronger than in earlier simulations.

The sizes and shapes of the thousands of galaxies that form in the EAGLE simulation are also similar to those of galaxies that astronomers observe in the Universe. "The universe generated by the computer is just like the real thing. There are galaxies everywhere, with all the shapes, sizes and colours I've seen with the world's largest telescopes. It is incredible. In the EAGLE universe I can even press a button to make time run backwards," says coauthor Richard Bower from Durham University.

Having developed a simulation which produces galaxies with characteristics similar to observed galaxies, astronomers can now study the evolution of individual galaxies in detail. "This is the start of a new era for us," says coauthor Rob Crain from Liverpool John Moores University. "We can now manipulate the conditions of the Universe and study the evolution of galaxies throughout the past 14 billion years."

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