"We're interested in biodetection that needs to be performed outside of the laboratory," said team leader Brian Cunningham, a professor of electrical and computer engineering and of bioengineering at the U. of I. "Smartphones are making a big impact on our society - the way we get our information, the way we communicate. And they have really powerful computing capability and imaging. A lot of medical conditions might be monitored very inexpensively and non-invasively using mobile platforms like phones. They can detect molecular things, like pathogens, disease biomarkers or DNA, things that are currently only done in big diagnostic labs with lots of expense and large volumes of blood."

The wedge-shaped cradle contains a series of optical components - lenses and filters - found in much larger and more expensive laboratory devices. The cradle holds the phone's camera in alignment with the optical components.

At the heart of the biosensor is a photonic crystal. A photonic crystal is like a mirror that only reflects one wavelength of light while the rest of the spectrum passes through. When anything biological attaches to the photonic crystal - such as protein, cells, pathogens or DNA - the reflected color will shift from a shorter wavelength to a longer wavelength.

For the handheld iPhone biosensor, a normal microscope slide is coated with the photonic material. The slide is primed to react to a specific target molecule. The photonic crystal slide is inserted into a slot on the cradle and the spectrum measured. Its reflecting wavelength shows up as a black gap in the spectrum. After exposure to the test sample, the spectrum is re-measured. The degree of shift in the reflected wavelength tells the app how much of the target molecule is in the sample. See a video of the app in action at http://www.youtube.com/watch?v=Kh7MUjIYuyw.

The entire test takes only a few minutes; the app walks the user through the process step by step. Although the cradle holds only about $200 of optical components, it performs as accurately as a large $50,000 spectrophotometer in the laboratory. So now, the device is not only portable, but also affordable for fieldwork in developing nations.

In a paper published in the journal Lab on a Chip, the team demonstrated sensing of an immune system protein, but the slide could be primed for any type of biological molecule or cell type. The researchers are working to improve the manufacturing process for the iPhone cradle and are working on a cradle for Android phones as well. They hope to begin making the cradles available next year.

Cunningham's group is now collaborating with other groups across campus at the U. of I. to explore applications for the iPhone biosensor. The group recently received a grant from the National Science Foundation to expand the range of biological experiments that can be performed with the phone, in collaboration with Steven Lumetta, a professor of electrical and computer engineering and of computer science at the U. of I. They are also are also working with food science and human nutrition professor Juan Andrade to develop a fast biosensor test for iron deficiency and vitamin A deficiency in expectant mothers and children.

In addition, Cunningham's team is working on biosensing tests that could be performed in the field to detect toxins in harvested corn and soybeans, and to detect pathogens in food and water.

"It's our goal to expand the range of biological experiments that can be performed with a phone and its camera being used as a spectrometer," Cunningham said. "In our first paper, we showed the ability to use a photonic crystal biosensor, but in our NSF grant, we're creating a multi-mode biosensor. We'll use the phone and one cradle to perform four of the most widely used biosensing assays that are available."

Cunningham also is affiliated with the Institute for Genomic Biology, the Beckman Institute for Advanced Science and Technology, and the Micro and Nanotechnology Laboratory, all at the U. of I.

PRS was developed in order to preserve fuel for an eventual recovery effort once a second wheel failed. This state uses thrusters to control the pointing of the spacecraft, tipping it towards the sun and letting the solar pressure tip it back away, resembling the motion of a pendulum. This is a very fuel-efficient mode, and it also provides an on-demand telemetry link to allow engineers to monitor and command the spacecraft. With nearly a week of PRS operations, the fuel usage appears to be on the low end of our estimates, allowing time for recovery planning.

The operations staff at Ball Aerospace did a wonderful job at developing and implementing PRS. As a result, the spacecraft is not in an emergency condition, and work can be conducted at a more deliberate pace. For the next week or so, we will contact the spacecraft on a daily basis to ensure PRS continues to operate as expected.

Over the coming weeks, an anomaly response team (ART) will evaluate wheel recovery options. The ART includes members from NASA Ames, Ball Aerospace, the Jet Propulsion Laboratory and UTC, the wheel manufacturer. This team has access to a broader reach of experts throughout NASA and industry, and will manage the wheel recovery efforts.

The team will continue to analyze recent telemetry received from the spacecraft. This analysis, and any planned recovery actions, will take time, and will likely be on the order of weeks, possibly months. Any planned commanding will first be vetted on the spacecraft test bed to validate command operability.

For now, PRS is working very well and keeping Kepler safe. We will provide updates on significant changes as the plan develops.

We are grateful to all our followers for their well wishes and support!

Regards,
Roger

Although the cold, thin atmosphere Mars has now means that liquid water cannot last on its surface long, orbital images from NASA's Mariner 9 mission and many other findings since then suggest Mars was once covered in rivers and seas, and that water may have even flowed there recently. Mars also has an atmosphere possessing carbon and nitrogen, essential elements for life as we know it, and organic molecules -- the carbon-based compounds that building blocks of life such as proteins and DNA are made from -- are expected to rain down in meteorites onto Mars, potentially once serving as the raw material for life.

NASA's Viking landers failed to find organic compounds or active microbes on Mars in the 1970s. However, in the last five years, NASA's Phoenix lander unexpectedly discovered that perchlorates seemed common in Martian dirt. Perchlorates are thermally reactive compounds that would destroy organic compounds when heated with them, which the Viking probes did when they analyzed dirt they'd scooped up. As such, the fact Viking did not find organics is no longer conclusive evidence that organics are absent on Mars.

One of the best places to potentially find signs of life or "biomarkers" on Mars is within its near-surface ice, which the Mars Odyssey orbiter revealed is widespread. Such ground ice on Earth is good at preserving organic compounds and biological material -- indeed, experiments have suggested it can preserve living cells for up to millions of years. Ice can also protect organic biomarkers from destruction from radiation from space and harsh chemicals on Mars.

"Why search for a second genesis of life?" McKay asked. "The implication is that life is common in the universe."

As such, McKay and his colleagues have spent about a decade developing the Icebreaker Life mission to Mars. The spacecraft would drill up to about 3 feet (1 meter) down and scan ice shavings for organic biomarkers -- molecules that would be conclusive evidence of life, ones too complex to be produced non-biologically. Discovering any organic biomarkers such as enzymes would not only be evidence of life, but also shed light on the biology of any putative organisms, potentially yielding hints to their genetics and metabolism.

An ideal region for the Icebreaker Life mission to drill would actually be the area where Phoenix landed in 2008. The ice-cemented ground in the northern plains of Mars are the most recently habitable places currently known on Mars -- the atmospheric pressure there is high enough to keep water from automatically boiling away. And as recently as 5 million years ago, Mars was tilted in relation to the Sun enough for its polar regions to receive roughly the same level of summer sunlight as Earth's polar regions do nowadays, so ice might have melted.

"This mission focuses on a far more recent time period of Mars than almost any other mission has. And that is wonderful," said planetary scientist Norbert Schorghofer at the University of Hawaii at Manoa, who did not take part in this research.

The Icebreaker Life drill is rotary-percussive, meaning it both spins and hammers. The drill bit has a heat sensor to detect if the ice is close to melting; the drill will slow or stop to prevent melting, since the water could refreeze and lock the drill. Using a separate robotic arm, the lander could pack samples into a capsule that a future mission could return to Earth.

After every 2 inches (5 centimeters) the drill goes into the ground, a brush collects samples off the drill. A battery of instruments can then analyze this material. For instance, the Signs of Life Detector (SOLID) can detect whole cells, complex organic molecules, and simple compounds of potential biological origin with the aid of a digital camera and the latest generation of lab-on-a-chip technology that essentially shrinks a lab's worth of beakers, flasks and other equipment to fit onto microchips for chemistry experiments.

Other potential instruments can measure acidity, alkalinity, dissolved salts and elemental composition, or use lasers to vaporize samples and scan the gas for organic molecules at low enough temperatures for them not to react with perchlorates. The way compounds soluble in water are spread out in the dirt could shed light on how liquid water might once have flowed on Mars.

Analyses of perchlorates could be especially useful. A number of microbes on Earth are known to live off perchlorates in combination with iron found in volcanic rock, so any microbes on Mars could have done the same thing, the researchers noted. Moreover, perchlorates are toxic to humans, so even if no life is found on Mars, learning more about the chemistry and distribution of perchlorates there might be important for any human missions to the Red Planet.

McKay and his colleagues tested the drill up to 3 feet (1 m) depth at Mars atmospheric pressure and against a wide range of materials, including ice, icy soils, icy soils with rocks, and rocks. They also tested it in the Arctic and the Antarctic, where the ice-cemented ground mimics Mars. In all cases, the drill reached 3 feet (1 m) in depth after about an hour.

The Icebreaker Life mission currently uses the same design as the NASA's solar-powered Phoenix spacecraft with only minor adjustments, and would land near the Phoenix site, operating only during polar summers, the researchers said. Their scenario involves a launch in December 2018 and landing in August 2019.

The scientists also noted the Icebreaker Life payload could accompany other Mars landing systems. For instance, while the SpaceX Dragon capsule is aimed primarily at delivering crew and cargo to the International Space Station, it was also designed to land on Mars, and could deliver the Icebreaker Life mission there. The mission does not have to land at the poles, and does not even have to drill into ice -- for instance, if any massive salt deposits are found on Mars, salt could be nearly as good a preservative for life as ice.

McKay cautioned Mars might neither have life now nor ever had it in the past. In addition, critics might say "we are advocating the search for organic biomarkers and we do not yet have direct evidence for organics. This is a valid criticism," McKay said.

Nevertheless, in the hope a future Icebreaker mission could discover signs of life on Mars, "we continue to develop the drill, the sample handling tools and the biomarker detection instrument," McKay said. The researchers would like to improve how deep Icebreaker can drill -- "right now we're only 1 meter deep. I would like to be deeper," McKay said.

"A question that needs be asked for every life detection mission is: What will we learn if no life is detected?" Schorghofer asked. "For the Icebreaker mission, the answer is delightfully clear -- we will learn a tremendous amount about Mars' recent climate history."

However, the current government financial crisis might doom the Icebreaker Life mission more than any threats on Mars.

"From a technical point of view, it is perfectly possible," Schorghofer added. "From a budgetary and programmatic point of view, it is unlikely to launch as soon as 2018."

The scientists detailed their findings online April 5 in the journal Astrobiology.

Charles Q. Choi, Astrobiology Magazine

"It has become common for top-notch studies to report genealogies that strongly contradict each other in where certain organisms sprang from, such as the place of sponges on the animal tree or of snails on the tree of mollusks," said Antonis Rokas, Cornelius Vanderbilt Chair in Biological Sciences at Vanderbilt University.

In a study published online May 8 by the journal Nature, Rokas and graduate student Leonidas Salichos analyze the reasons for these differences and propose a suite of novel techniques that can resolve the contradictions and provide greater accuracy in deciphering the deep branches of life's tree.

"The study by Salichos and Rokas comes at a critical time when scientists are grappling with how best to detect the signature of evolutionary history from a deluge of genetic data. These authors provide intriguing insights into our standard analytical toolbox, and suggest it may be time to abandon some of our most trusted tools when it comes to the analysis of big data sets.

This significant work will certainly challenge the community of evolutionary biologists to rethink how best to reconstruct phylogeny," said Michael F. Whiting, program director of systematics and biodiversity science at the National Science Foundation, which funded the study.

To gain insight into this paradox, Salichos assembled and analyzed more than 1,000 genes - approximately 20 percent of the entire yeast genome - from each of 23 yeast species. He quickly realized that the histories of the 1,000-plus genes were all slightly different from each other as well as different from the genealogy constructed from a simultaneous analysis of all the genes.

"I was quite surprised by this result," Salichos pointed out.

By adapting an algorithm from information theory, the researchers found that they could use these distinct gene genealogies to quantify the conflict and focus on those parts of the tree that are problematic.

In broad terms, Rokas and Salichos found that genetic data is less reliable during periods of rapid radiation, when new species were formed rapidly. A case in point is the Cambrian explosion, the sudden appearance about 540 million years ago of a remarkable diversity of animal species, without apparent predecessors. Before about 580 million years ago, most organisms were very simple, consisting of single cells occasionally organized into colonies.

"A lot of the debate on the differences in the trees has been between studies concerning the 'bushy' branches that took place in these 'radiations'," Rokas said.

The researchers also found that the further back in time they went the less reliable the genetic data becomes. "Radioactive dating methods are only accurate over a certain time span," said Rokas. "We think that the value of DNA data might have a similar limit, posing considerable challenges to existing algorithms to resolve radiations that took place in deep time."

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The research was supported by National Science Foundation CAREER award DEB-0844968.

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