Astronomers are using tree rings as a historical record of solar activity — and they've found that the Sun was much more active in the past.

Our Sun is not the faithfully constant light source it appears to be. Solar activity varies in a fairly regular cycle of 11 years, most notably in the periodic rise and fall in the number of sunspots. Though German astronomer Samuel Heinrich Schwabe discovered the cycle in the 19th century, sunspot observations commenced about 400 years ago with Galileo Galilei, and the solar cycle has been traced back to these early observations.

Now, a team of scientists based in Switzerland has successfully reconstructed the 11-year Schwabe cycle all the way back to the year AD 969, using the Sun's imprint on ancient trees on Earth. Their report appears in Nature Geoscience.

An international team of researchers has found what they believe to be the pathogen that has been killing chimpanzees at a Sierra Leone sanctuary for approximately 15 years. In their paper published in the journal Nature Communications, the group describes their study of multiple samples of chimp tissue retrieved from some of the dead chimps and what they have found thus far.

Approximately 15 years ago, workers at Sierra Leone's Tacugama Chimpanzee Sanctuary began to see chimps in their sanctuary become ill from a new and mysterious ailment — alarmingly, every chimp that became ill died. In the beginning, the team thought that they had more than one pathogen on their hands because, for some chimps, the main symptoms were gastrointestinal stress while, for others, symptoms were clearly neurological. Over time, the team became convinced it was a single pathogen as they saw increasing numbers of chimps with both types of symptoms.

An upsurge of matter from deep beneath the Earth's crust could be pushing the continents of North and South America further apart from Europe and Africa, new research has found.

The plates attached to the Americas are moving apart from those attached to Europe and Africa by four centimetres per year. In between these continents lies the Mid-Atlantic Ridge, a site where new plates are formed and a dividing line between plates moving to the west and those moving to the east; beneath this ridge, material rises to replace the space left by the plates as they move apart.

Conventional wisdom is that this process is normally driven by distant gravity forces as denser parts of the plates sink back into the Earth. However, the driving force behind the separation of the Atlantic plates has remained a mystery because the Atlantic ocean is not surrounded by dense, sinking plates.

Researchers at the University of Maryland have turned ordinary sheets of wood into transparent material that is nearly as clear as glass, but stronger and with better insulating properties. It could become an energy efficient building material in the future.

Wood is made of two basic ingredients: cellulose, which are tiny fibres, and lignin, which bonds those fibres together to give it strength.

Tear a paper towel in half and look closely along the edge. You will see the little cellulose fibres sticking up. Lignin is a glue-like material that bonds the fibres together, a little like the plastic resin in fibreglass or carbon fibre. The lignin also contains molecules called chromophores, which give the wood its brown colour and prevent light from passing through.

Early attempts to make transparent wood involved removing the lignin, but this involved hazardous chemicals, high temperatures and a lot of time, making the product expensive and somewhat brittle. The new technique is so cheap and easy it could literally be done in a backyard.


Starting with planks of wood a metre long and one millimetre thick, the scientists simply brushed on a solution of hydrogen peroxide using an ordinary paint brush. When left in the sun, or under a UV lamp for an hour or so, the peroxide bleached out the brown chromophores but left the lignin intact, so the wood turned white.

Changes in Mar's geography always attract significant scientific and even public attention. A hope for signs of liquid water (and therefore life) is likely one of the primary driving forces behind this interest. One particularly striking changing feature is the Recurring Slope Lineae (RSL) originally found by the Mars Reconnaissance Orbiter (MRO). Now, scientists at the SETI Institute have a modified theory for where those RSLs might develop - a combination of water ice and salt just under the Martian surface.

According to the SETI team, led by Senior Research Scientist Janice Bishop, there is a two step process going on that creates these RSLs. First, underground water ice must mix with a combination of chlorine salts and sulfates to create a type of slurry that destabilizes the regolith in the area. Then, the dry wind and dust storms of Mars take over, blowing the destabilized material into new patterns across the Martian surface.

The Arctic Ocean was once a pool of fresh water capped with an ice shelf half as thick as the Grand Canyon is deep.

If that's hard to envision, don't despair. Scientists were surprised at the discovery, published Wednesday (Feb. 3) in the journal Nature, as well. The trick to envisioning this odd arrangement is to think about the relationship between ice sheets and the ocean. When ice sheets melt, they dump water into the ocean, raising the sea level. But when ice sheets grow, as they have during Earth's glacial periods, sea level drops.


Now, new research shows that in these eras of lower sea level, the Arctic Ocean's connection to the Pacific and Atlantic was very limited, with Greenland, Iceland, and northern Europe and Siberia acting as the rim of a bowl containing the Arctic. (Ice itself could have further restricted circulation.) Land and sea alike were overlain with an ice sheet 2,952 feet (900 meters) thick.

The modern world is powered by electrical circuitry on a "chip" — the semiconductor chip underpinning computers, cell phones, the internet, and other applications. In the year 2025, humans are expected to be creating 175 zettabytes (175trillion gigabytes) of new data. How can we ensure the security of sensitive data at such a high volume? And how can we address grand-challenge-like problems, from privacy and security to climate change, leveraging this data, especially given the limited capability of current computers?

A promising alternative is emerging quantum communication and computation technologies. For this to happen, however, it will require the widespread development of powerful new quantum optical circuits­; circuits that are capable of securely processing the massive amounts of information we generate every day. Researchers in USC's Mork Family Department of Chemical Engineering and Materials Science have made a breakthrough to help enable this technology.

While a traditional electrical circuit is a pathway along which electrons from an electric charge flow, a quantum optical circuit uses light sources that generate individual light particles, or photons, on-demand, one-at-a-time, acting as information carrying bits (quantum bits or qubits). These light sources are nano-sized semiconductor "quantum dots"-tiny manufactured collections of tens of thousands to a million atoms packed within a volume of linear size less than a thousandth of the thickness of typical human hair buried in a matrix of another suitable semiconductor.

As the average length of women's menstrual cycles matches the moon's 29.5-day waxing and waning cycle, many cultures associated the moon with fertility. The celestial body's influence on humans biology had largely been dismissed as myth, but several recent studies have linked lunar phases with sleep and moods. In a study published January 27 in Science Advances, researchers analyzed long-term data from women and found that for some their periods synced with lunar light and gravity cycles at certain times in their lives.

"[The study] has not completely settled the debate," says Kristin Tessmar-Raible, a chronobiologist at the University of Vienna who was not involved with the research. "But it's really cool that this puts fresh spirit into the whole discussion: is the moon — yes or no — [affecting] human biology."

Charlotte Helfrich-Förster, a chronobiologist at Julius-Maximilians University of Würzburg in Germany and the lead author of the study, says she was initially "skeptical" of a link between lunar menstrual cycles. "On the other hand, it is very interesting that the [menstrual] cycle length is more or less the moon cycle length, and it's known from many studies that animals — at least marine organisms — rely on the moon for synchronizing their reproduction," she says. To examine whether moon cycles influence human menstrual cycles, Helfrich-Förster and her colleagues examined 22 women who recorded the date their period started for five to 32 years.

As the moon makes its 27.3-day journey around the Earth, it exhibits three different lunar cycles: the luminance cycle, the perigee-apogee cycle, and the lunar standstill cycle. The position of Earth's natural satellite in relation to the sun changes during its orbit, causing the familiar luminance cycle between the new and full moon every 29.5 days. This celestial circuit is elliptical, thereby altering the moon's gravitational tug as it swings from perigee, the closest point on the loop around Earth, to apogee, its most distant, every 27.5 days. Additionally, this orbit is tilted in relation to the Earth's axis, causing varying gravitational effects on the Southern and Northern hemispheres across the 27.3-day lunar standstill cycle.

And many other things genetic. The presenters provide revealing information about how our understanding of genetics has changed in the last seven decades. Very easy to follow:

The human genome is much more complex than anyone imagined. In fact, the level of complexity argues directly against any sort of evolutionary origin for the code that makes us.

An international team, led by the Bavarian State Collection of Zoology (ZSM-SNSB), has discovered a minuscule new species of chameleon. The sole known, apparently adult male of the new species has a body size of just 13.5 mm, making it the smallest known male of the roughly 11,500 known non-avian reptiles. A comparison with 51 other chameleon species showed that the new species has exceptionally large genitals. The study was published in the open access journal Scientific Reports.

On an expedition in the North of Madagascar, a joint team of German and Malagasy scientists came across a new contender for the title of 'world's smallest reptile." They have named the new species Brookesia nana. "At a body length of just 13.5 mm and a total length of just 22 mm including the tail, the male nano-chameleon is the smallest known male of all 'higher vertebrates"' says Frank Glaw, Curator of Herpetology at the Bavarian State Collection of Zoology (ZSM-SNSB) and first author on the study. The female is larger at 19 mm body length and 29 mm total length. In spite of intensive efforts, the authors were only able to find two individuals.