When began her career as a neurobiologist at Stanford University School of Medicine in California, she kept seeing fantastic female students having their confidence knocked. Many dropped out of science altogether after their PhDs. 鈥淚 felt compelled to do something,鈥� she says.

So, three years ago, Raymond started a , looking at gender issues in neuroscience. The group shares its resources online, and since its initiation similar groups have sprung up in the university鈥檚 linguistics and biochemistry departments. Clearly, gender is a topic that a lot of people want to talk about.

It鈥檚 easy to see why. Over the past 20 years in the US, . However, that growth hasn鈥檛 followed through into the nation鈥檚 senior science and engineering faculties, where .

In certain fields, the dropout figures soar even earlier in women鈥檚 careers. While women hold about 20 per cent of bachelor degrees in engineering in the US, they only go on to make up about 11 per cent of the engineering workforce. The science community is losing a talented workforce. How can we plug the leaking pipeline?

The female force

Beyond the moral imperative to be fair, there is no doubt that organizations with limited diversity are weaker as a result. A lack of gender balance has been found to affect everything from the quality of professional practice to the productivity of a team. One found that women leaders in the boardroom bring empathy, intuition and communication skills that men do not. , an organizational psychologist at Carnegie Mellon University in Pittsburgh, Pennsylvania, has even shown that the collective intelligence of teams 鈥� a predictive measure of performance much like a group IQ 鈥� is correlated with the number of women on them. Her work suggests that a better gender balance makes for smarter groups.

So, if the benefits are clear, why are women underrepresented in science? One reason is that stereotypes hinder their career growth. These gender-based notions can be reinforced even without any explicit comments from either sex, and are often the result of numerous subtle cultural norms. These can shape people鈥檚 concepts of science and scientists well before grad school, and their effects can be remarkable. Merely being told that women are worse at math stunts female performance on math tests, for example.

As long as these stereotypes persist, women will have a weight on their minds at work, says , a social psychologist at the University of California, Los Angeles. 鈥淚t鈥檚 an additional cognitive burden that men don鈥檛 have.鈥�

Women can face bias as well as general stereotypes. Successive small slights during hiring and career progression can add up to a large disadvantage throughout a woman鈥檚 career.

What makes this bias hard to avoid, however, is that both perpetrators and victims may initially be unconscious of it. 鈥淲e鈥檙e wrong to think we know when we鈥檙e being biased or not,鈥� says , a systems neuroscientist at Cold Spring Harbor Laboratory in New York. 鈥淲e like this idea that we know all the factors that weigh in on our decisions, but as someone who studies decision-making, I can say with authority that we don鈥檛.鈥�

As a result, female job applicants have a tougher time landing research placements. To investigate the unconscious bias of science faculty, at Yale University in Connecticut sent research groups across the US r茅sum茅s from fictional applicants. Although the applicants鈥� qualifications were identical, r茅sum茅s from 鈥淛ohn鈥� were received more favourably than those from 鈥淛ennifer鈥�. Both male and female .

鈥淭he problem is that at the point of evaluation, we give men a little more credit than women,鈥� says , a cognitive psychologist at Hunter College in New York. 鈥淚t鈥檚 as if men have a little plus sign next to their names and women have a minus.鈥�

Breaking the mold

Fortunately, countering bias can be simple. Increasing the profile of female scientists is one solution. Churchland has developed 鈥� a roster of qualified female speakers she drafted when her male colleagues complained about a lack of diversity at computational neuroscience meetings.

Education offers a more long-term solution, says Erin Cadwalader, a policy fellow at the non-profit in Alexandria, Virginia. A better awareness of unconscious bias can help decision-makers on faculty boards and recruitment teams avoid biased hiring practices.

AWIS is one of a growing number of organizations that offers mentoring and support to women scientists. Field-specific organizations, such as the and the , mentor and advocate for their female members, for example.

Behind these initiatives there is a stronger political movement. The , under review by the Science, Space, and Technology Committee of the House of Representatives, would require federal science agencies to draft new policies to reduce bias during grant reviews.

The benefits of keeping women in science will be significant. 鈥淭rying to get rid of bias is not just about being nice or fair. It鈥檚 really about trying to take full advantage of the talent pool that鈥檚 available,鈥� says Raymond.

鈥淲hen we鈥檙e losing part of the talent pool, we鈥檙e losing not just those people, we鈥檙e losing the discoveries they would have made had we kept them in the game.鈥�

The basic unit of matter could become the basic unit of computing. A lone atom of phosphorus embedded in a sheet of silicon has been made to act as a transistor.

It is not the first , but it can be much more precisely positioned than its predecessors, potentially making it a lot more useful.

鈥淚t鈥檚 an absolutely fantastic piece of engineering,鈥� says physicist at the University of Maryland, who was not involved in the work.

Elaborate production methods would initially prevent single-atom phosphorus transistors from being a worthwhile addition to traditional computers, but they may be necessary one day. The devices could also find an application in futuristic, super-speedy quantum computers.

A transistor is essentially a lump of conducting material sitting between two electrodes that acts as a switch. A pulse of voltage is supplied by a further electrode,鈥漮pening鈥� the switch and allowing current to flow through the transistor.

Wiggling atom

Combining transistors on a chip produces logic circuits that can carry out computations. A goal shared by computer chip makers is to keep shrinking the transistor: squeeze ever more onto a single chip and you increase its computational power.

To dictate the exact position of their single atom, at the University of New South Wales, Australia, and colleagues started by covering a silicon sheet with a layer of hydrogen. Then they used the tip of a scanning tunnelling microscope to remove hydrogen atoms according to a precise pattern. They exposed two perpendicular pairs of exposed silicon strips plus a tiny rectangle made of just six silicon atoms that sat at the junction between these strips (see diagram, right).

Adding phosphine gas (PH₃) and heating caused phosphorus atoms, which are conducting, to bind to these exposed areas of silicon. In the case of the rectangle only one atom inserted itself into the silicon network.

The result was four phosphorus electrodes and a single phosphorus atom.

Boutique operation

One pair of electrodes was separated by a 108-nanometre gap. Creating a voltage between them allowed current to flow between the two perpendicular electrodes 鈥� separated from each other by just 20 nanometres, through the single phosphorus atom, which acted as a transistor.

Kane points out that the atomic transistor works at temperatures below 1 kelvin and that fabrication is difficult. 鈥淚t鈥檚 a very slow, boutique operation to make one of these,鈥� he says.

Simmons agrees, but counters that the traditional computer makers may be forced to adopt this technology if they want to make ever smaller chips. 鈥淭his is one of the only techniques that allows you to make single atom devices,鈥� she says.

Physicist of the University of Pittsburgh in Pennsylvania reckons the future of single atom transistors lies in quantum computers. The spin of the electrons in isolated phosphorus atoms could serve as qubits, the quantum equivalent of the bits in today鈥檚 computers. Controlling the interaction between qubits requires knowing the exact location of each one. Now that the location of individual atoms can be controlled, the next challenge is to link two of these transistors, Levy says.

Watch a video explaining was made

Journal reference:

These fish may lack a conversation partner, though, if underwater noise pollution covers their quiet calls.

More than 50 years ago, scientists dissecting deep-water fish noticed that they had sound-producing muscles like those in noisy, shallow-water fish. However, recording sound in deep water is difficult, so it was unknown if fish actually used those muscles to create calls.

Listening to fish

of the University of Massachusetts in Amherst and his colleagues have now placed an underwater microphone on the Atlantic ocean floor .

The researchers attached the microphone to an MP3 player and mounted the device in a plastic case. Fisheries workers in Massachusetts placed the recorder inside a crab trap, which was lowered onto the North American continental shelf, 682 metres below sea level.

The 24-hour recording captured at least 12 unknown grunting, drumming and duck-like sounds with frequencies below 1.2聽kilohertz (listen to them here) 鈥� within the range for fish calls or potentially low-frequency whale calls.

Conjugal conversations

Like their shallow-water cousins, deep-water fish may call each other during their mating season. These conjugal conversations may be especially important to deep-water fish because there is little light down there to find potential mates by.

If these fish communicate through sound, background noise from passing ships could drown out their conversations. But before the full effect of noise pollution is known, the aquatic chatterboxes must first be identified and their banter translated. 鈥淭his is a whole area of the ecology of these fishes that we know almost nothing about,鈥� says Rountree.

鈥淪ome of the sounds are almost for sure from fish because of their characteristics,鈥� says zoologist of Virginia Commonwealth University in Richmond, who was not involved in the study. All deep-water fish with sound-producing muscles probably vocalise, though, and any of them could be responsible for the calls, he adds. 鈥淚t鈥檚 so tough making a living in the deep sea that [fish] aren鈥檛 going to have a frivolous organ that does nothing.鈥�

Reference: , published by Springer

KOI-54 was identified in January. Its brightness pulses every 42 days, when its two stars pass especially close to one another and the gravity of each deforms the other. The sides of the stars bulge, increasing the surface area observed by the Kepler telescope and contributing to the brightness spike.

Although KOI-54 is some 1000 light years away from Earth, the Kepler telescope has now begun to pick up even smaller pulses in its brightness, beating 90 times faster than the main pulse.

Jim Fuller and of Cornell University in Ithaca, New York, told the at Moffett Field, California, that these micro-oscillations may bring more data on each star鈥檚 internal structure.

Astronomers have found the smallest planet ever detected in the habitable zone around a star like the sun.

The new planet was found with the Kepler telescope, which searches for signs that a star鈥檚 light has dimmed because a planet has passed between it and the telescope 鈥� an event called a transit.

See graphic: Planet hunter

鈥淭his discovery supports the growing belief that we live in a universe crowded with life,鈥� team member Alan Boss of the Carnegie Institution for Science said in a statement. 鈥淜epler is on the verge of determining the actual abundance of habitable, Earth-like planets in our galaxy.鈥�

The planet, named Kepler-22b, lies 600 light years away around a star of the same type (called ) as the sun. It is about 2.4 times as wide as Earth and orbits its star every 290 days, right in the middle of its star鈥檚 habitable zone, where liquid water can exist on an object鈥檚 surface.

Transit observations cannot pinpoint its mass, however. Astronomers have used other telescopes to search for signs that the planet鈥檚 gravitational tugs are causing its host star to wobble, but so far have not detected any wobbles. That means the planet鈥檚 mass must be less than 36 times that of the Earth.

It is close in size to a class of planets called super-Earths, which are up to about 2 times as wide as Earth. 鈥淲e have no planet like this in our solar system,鈥� says Bill Borucki, Kepler鈥檚 chief scientist at NASA鈥檚 Ames Research Center in Moffett Field, California. He announced the find on Monday at the at NASA Ames.

Just right

The planet could be rocky and could contain water, Borucki says.

But , a graduate student at MIT, says most planets of its width are more like small gas giant planets, with a substantial gas layer surrounding a rocky core. Kepler-22b 鈥渋s probably more like a small Neptune than a scaled-up version of Earth鈥�, Rogers told New 女生小视频.

Ground-based observations in mid-2012, when the patch of sky where the planet lies is more easily visible, could help astronomers nail down the planet鈥檚 mass. That will help them identify its composition.

Two previous rocky planet candidates have been found in the habitable zones of their stars, but in both cases the stars were cooler than the sun.

And neither candidate was found right in the middle of its star鈥檚 鈥淕oldilocks鈥� zone, which could boast the best conditions for hosting life as we know it. Kepler-22b鈥檚 surface is probably a balmy 22聽掳C, Borucki said.

Scanning for ET

The Kepler telescope has been staring at more than 150,000 stars between the constellations Cygnus and Lyra for the past 1000 days. The Kepler team has now found more than 2300 candidate exoplanets, about 1000 more than it reported in February. Ten of those span no more than about twice Earth鈥檚 width.

To confirm a new planet, scientists must observe three of its transits. Mission scientists saw the first transit of Kepler-22b three days after Kepler began collecting data in 2009. The third transit appeared in December 2010. 鈥淚t鈥檚 a great gift,鈥� Borucki said. 鈥淲e consider this our Christmas planet.鈥�

鈥淚t鈥檚 conceivable that these new planet candidates and their [potential] moons could have life,鈥� Borucki said.

The SETI Institute in Mountain View, California, will observe the new candidates with its Allen Telescope Array of radio telescopes in California in the hopes of detecting signals from any extraterrestrial civilisations there, said the institute鈥檚 . The array had been offline since April due to budget cuts but on Monday after raising funds by partnering with the US air force and .

Trees may get their beautiful shapes from battling the elements. A mathematical model shows that the pattern some branches make, first noted by Leonardo da Vinci, is the best at withstanding gusts of wind.

Da Vinci observed that at any height above the ground, the total cross section of some trees鈥� branches has roughly the same area as that of the trunk. This pattern was thought to accommodate the tree鈥檚 plumbing, as water flows fastest when the branched pipes can hold as much water as the original pipe. But at the University of California in San Diego thought trees contained too little plumbing to be the reason behind the pattern.

Instead he thought wind might play a role. So he built a model to simulate the bending forces exerted by the wind, and . The work will appear in .

The model could help architects design wind-resistant buildings that mimic tree branches, says plant biophysicist at Cornell University in Ithaca, New York.

Reference:

Just 160 atoms have been made to tie themselves into the smallest version of the pentafoil knot ever made. It鈥檚 also the most complicated knot ever achieved by a single molecule.

The knot, also known as the cinquefoil or Solomon鈥檚 knot, is a 鈥減rime鈥� knot鈥�. Its woven star shape contains five crossing points and cannot be built from smaller knots, similar to the way a prime number cannot be the product of smaller numbers. A version of the pentafoil knot features on the flags of Ethiopia and Morocco, giving it cultural as well as mathematical significance.

Chemists have previously created a prime knot called a trefoil, which has three crossing points. and colleagues at the University of Edinburgh, UK, wove the pentafoil using 鈥渘eedles鈥� made of positively charged iron ions attached to long, skinny organic-molecule 鈥渢hreads鈥�.

When the researchers added negatively charged chloride ions, these ions became hubs, each attracting exactly five needle-and-thread compounds. In the process of arranging themselves around the central hub, the metal ions folded the organic molecules over one another, braiding them into a woven star shape. Finally, chemical bonds formed that connected the strands at the points of the star, turning the whole arrangement into a single molecule.

Some day, the researchers would like to knit a whole surface of knotted molecules. 鈥淧erhaps we could make a chain-mail type of material in which, just like a suit of armour, you鈥檝e got a very strong but very flexible material,鈥� says Leigh.

Fractals make pretty posters, but they also describe stunning 3D molecular shapes.

A fractal describes a geometric shape that has the same patterns at many different size scales, like a branching bit of broccoli. Tiny leaves at the crown of the plant combine into small florets, which merge to form a full head of broccoli.

Chemists have built many highly branched molecules but created only a few that can be described by fractal equations.

at the University of Akron, Ohio, and colleagues created this molecular fractal out of ruthenium and iron atoms. At first glance, the molecule has two interlocking triangles, like a star of David. But a closer look reveals many differently sized hexagons.

To build the shape, ruthenium atoms form a hexagonal ring around a single ruthenium atom. These ruthenium complexes then aggregate into a larger hexagon. Finally, iron complexes link the six ruthenium clusters into the interlocking star pattern.

If this molecule conducts electricity in the right way, it could be an eye-catching way to improve energy storage.

Journal reference:

As well as super-shrinking everyday gadgets such as motors, molecules have also been massaged into shapes that are more mathematical than practical.

of New York University and colleagues mastered a molecule-sized version of one of the 13 鈥淎rchimedean solids鈥� 鈥� a family of symmetrical three-dimensional polyhedra attributed to the Greek mathematician.

The solid, a truncated octahedron, was built with tiny molecular tiles. One type of tile, ringed with chemical groups called guanidiniums, joined with another type ringed with sulphonates to form the shape through a connection of 72 hydrogen bonds.

The result is a hollow cage. By adding reactants to the tile mixture while cages were forming, the team also created inside them three metal 鈥渃omplexes鈥� containing bismuth, lead and mercury that had never been seen before. The cage easily dissolves to release the new complexes.

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