Amazing Science

In the quest for habitable planets outside our Solar System – also known as exoplanets – astronomers are currently focusing on rocky planets that don’t look like Earth. These planets orbit so-called M dwarfs – stars that are smaller than our Sun. In our universe, there are many more M dwarfs than there are sun-like stars, making it more likely that astronomers will discover the first habitable exoplanet around an M dwarf. Most planets orbiting these M dwarfs always face their star with the same side. As a result, they have permanent day and night sides. The day side is too hot to make life possible, while the night side is too cold.

Last year, KU Leuven researchers Ludmila Carone, Professor Rony Keppens, and Professor Leen Decin already showed that planets with permanent day sides may still be habitable depending on their 'air conditioning' system. Two out of three possible ‘air conditioning’ systems on these exoplanets use the cold air of the night side to cool down the day side. And with the right atmosphere and temperature, planets with permanent day and night sides are potentially habitable.

Researchers at the University of California, Riverside have developed a transparent “window to the brain” — a skull implant that is biocompatible, infection-resistant, and does not need to be repetitively replaced.

Part of the ongoing “Window to the Brain” project, a multi-institution, cross-disciplinary effort, the idea is to use transparent skull implants to provide laser diagnosis and treatment of a wide variety of brain pathologies, including brain cancers, traumatic brain injury, stroke, and neurodegenerative diseases, without requiring repeated craniotomies (a surgical operation in which a bone flap is temporarily removed from the skull to access the brain). Such operations are vulnerable to bacterial infections.

The researchers have developed a transparent version of the material yttria-stabilized zirconia (YSZ), a ceramic material used in hip implants and dental crowns.

The researchers implanted the material in a hamster, where it integrated into the host tissue without causing an immune response or other adverse effects, as they describe in a paper in the journal Nanomedicine: Nanotechnology, Biology and Medicine. The internal toughness of YSZ, which is more impact-resistant and biocompatible than the titanium, thermoplastic polymers, and glass-based materials developed by other researchers, makes it “the only transparent skull implant that could conceivably be used in humans,” according to the researchers.

Hokkaido University researchers have designed a crystal material that continually flips between two positions like a paddle, propelling an attached structure, when stimulated by blue light. It could lead to bio-inspired microrobots that deliver drugs to target tissues, for example.

The team made azobenzene-oleic acid crystals, composed of an organic compound called azobenzene, commonly used in dye manufacturing, and oleic acid, commonly found in cooking oil. Azobenzene molecules take two structurally different forms: cis and trans, and they were found to switch back and forth when stimulated by the light.

The frequency of the motion also increased with increased light intensity. Some crystal complexes they created even exhibited swimming-like motions in the water, the researchers report. Previously reported light-responsive materials have been limited in their ability to deform, the researchers noted.

“The importance of this study lies in the realization of macroscopic self-oscillation by the repeated reversible reaction of a molecular machine with the cooperative transformation of a molecular assembly,” the researchers note in a paper published in the journal Angewandte Chemie.

“These results provide a fundamental strategy for constructing dynamic self-organizations in supramolecular systems to achieve bioinspired molecular systems.”

Using a small quantum system consisting of three superconducting qubits, researchers at UC Santa Barbara and Google have uncovered a link between aspects of classical and quantum physics thought to be unrelated.

"It's kind of surprising because chaos is this totally classical concept—there's no idea of chaos in a quantum system," Charles Neill, a researcher in the UCSB Department of Physics and lead author of a paper that appears in Nature Physics. "Similarly, there's no concept of entanglement within classical systems. And yet it turns out that chaos and entanglement are really very strongly and clearly related."

Initiated in the 15th century, classical physics generally examines and describes systems larger than atoms and molecules. It consists of hundreds of years' worth of study including Newton's laws of motion, electrodynamics, relativity, thermodynamics as well as chaos theory—the field that studies the behavior of highly sensitive and unpredictable systems. One classic example of chaos theory is the weather, in which a relatively small change in one part of the system is enough to foil predictions—and vacation plans—anywhere on the globe.

At smaller size and length scales in nature, however, such as those involving atoms and photons and their behaviors, classical physics falls short. In the early 20th century quantum physics emerged, with its seemingly counterintuitive and sometimes controversial science, including the notions of superposition (the theory that a particle can be located in several places at once) and entanglement (particles that are deeply linked behave as such despite physical distance from one another).

How did the universe come into existence, a Big Bang or a Big Bounce? In other words, is the reality we currently inhabit brand-new, or is the universe cyclical — inflating and deflating like a balloon over and over again?

In a new study published Wednesday in the Physical Review Letters, a team of international scientists has attempted to answer this eternally vexing question. The paper, titled “Perfect Quantum Cosmological Bounce,” argues that the cosmos we exist in may have been formed from an older collapsing universe.

Although the Big Bounce idea has been around, in one form or the other, since 1922, scientists have faced a key obstacle in explaining how the universe transitions from a contracting to an expanding phase and avoids becoming an “infinite point” in the process. The problem is something that also plagues cosmological models that describe the Big Bang — how does the universe, and everything in it, emerge from a singularity, which, by definition, is a single point that occupies no space at all.

“This is a problem,” co-author Neil Turok, director of the Perimeter Institute for Theoretical Physics in Canada, said in a statement. “The standard cosmology begins with an impossibility.” The present-day universe obeys two seemingly incompatible laws — with quantum mechanics governing the behavior of subatomic particles and relativity describing how clumps of atoms — humans, stars and galaxies — behave. Formulating an all-encompassing Theory of Everything, one that resolves the apparent contradictions between quantum mechanics and relativity has, for the longest time, been the holy grail of particle physics.

The study, which, among other things, attempts to resolve this seemingly insurmountable problem, states that the universe, in its earliest stages, would have exhibited a phenomenon known as conformal symmetry — wherein physical laws governing the entire universe would also have worked at the scale of subatomic particles.

If this is true, the researchers argue, the exact moment of the “bounce” from contraction and expansion can be explained using well-established mathematical model that describes quantum tunneling — a phenomenon in which a particle tunnels through a barrier it cannot cross. According to the researchers, the universe achieved (and will achieve) this transition by approaching the singularity point and then skipping over it by temporarily accessing another dimension.

Every time you take a photograph, your camera detects more than a billion photons. For a basic one-megapixel camera, that's more than 1,000 photons per pixel. Now in a new study, researchers have developed an algorithm that is so efficient that it can generate high-quality 3D images using a single-photon camera that detects just one signal photon per pixel.

The researchers, led by Jeffrey Shapiro, a professor of electrical engineering and computer science at the Massachusetts Institute of Technology (MIT), along with coauthors at MIT, Politecnico di Milano, and Boston University, have published a paper on the new photon-efficient approach to imaging with a single-photon camera in a recent issue of Nature Communications.

"Our work shows that we can use these new photon-counting cameras at much lower fluxes and much higher efficiencies than previously thought," Shapiro explains. Compared to other camera-based 3D imaging techniques that have recently been developed, the new framework has the highest photon efficiency to date, resulting in a visibly better reconstruction accuracy and an order of magnitude better depth resolution.

To demonstrate how the new single-photon imaging algorithm works in low-light environments, the researchers illuminated a scene of interest (such as a mannequin and sunflower) with a pulsed laser that emits low-light pulses every 50 nanoseconds. A light diffuser spatially spreads out the pulses so that they flood the entire scene.

She lived to 115, but a study of Hendrikje van Andel-Schipper's blood hints at factors limiting lifespan

Death is the one certainty in life – a pioneering analysis of blood from one of the world’s oldest and healthiest women has given clues to why it happens. Born in 1890, Hendrikje van Andel-Schipper was at one point the oldest woman in the world. She was also remarkable for her health, with crystal-clear cognition until she was close to death, and a blood circulatory system free of disease. When she died in 2005, she bequeathed her body to science, with the full support of her living relatives that any outcomes of scientific analysis – as well as her name – be made public. Researchers have now examined her blood and other tissues to see how they were affected by age.

What they found suggests, as we could perhaps expect, that our lifespan might ultimately be limited by the capacity for stem cells to keep replenishing tissues day in day out. Once the stem cells reach a state of exhaustion that imposes a limit on their own lifespan, they themselves gradually die out and steadily diminish the body’s capacity to keep regenerating vital tissues and cells, such as blood.

In van Andel-Schipper’s case, it seemed that in the twilight of her life, about two-thirds of the white blood cells remaining in her body at death originated from just two stem cells, implying that most or all of the blood stem cells she started life with had already burned out and died. “Is there a limit to the number of stem cell divisions, and does that imply that there’s a limit to human life?” asks Henne Holstege of the VU University Medical Center in Amsterdam, the Netherlands, who headed the research team. “Or can you get round that by replenishment with cells saved from earlier in your life?” she says.

The other evidence for the stem cell fatigue came from observations that van Andel-Schipper’s white blood cells had drastically worn-down telomeres – the protective tips on chromosomes that burn down like wicks each time a cell divides. On average, the telomeres on the white blood cells were 17 times shorter than those on brain cells, which hardly replicate at all throughout life.

The team could establish the number of white blood cell-generating stem cells by studying the pattern of mutations found within the blood cells. The pattern was so similar in all cells that the researchers could conclude that they all came from one of two closely related “mother” stem cells.

“It’s estimated that we’re born with around 20,000 blood stem cells, and at any one time, around 1000 are simultaneously active to replenish blood,” says Holstege. During life, the number of active stem cells shrinks, she says, and their telomeres shorten to the point at which they die – a point called stem-cell exhaustion.

Holstege says the other remarkable finding was that the mutations within the blood cells were harmless – all resulted from mistaken replication of DNA during van Andel-Schipper’s life as the “mother” blood stem cells multiplied to provide clones from which blood was repeatedly replenished. She says this is the first time patterns of lifetime “somatic” mutations have been studied in such an old and such a healthy person. The absence of mutations posing dangers of disease and cancer suggest that van Andel-Schipper had a superior system for repairing or aborting cells with dangerous mutations.

The study is novel because it is the first to investigate the accumulation of somatic mutations within the tissues of an old individual, says Chris Tyler-Smith of the Wellcome Trust Sanger Institute in Hinxton, UK. “This contrasts to the germ-line mutations [present at birth] measured in previous studies,” he says.

In the paper, the researchers estimate that around 100 generations of capuchins have used this tradition of stone tools. They compared tools used by modern capuchins with the oldest excavated examples, finding they are similar in terms of weight and materials chosen. This apparent lack of change over hundreds of years suggests monkeys are ‘conservative’, preferring not to change the technology used, unlike humans living in the same region, says the paper.

Lead author Dr Michael Haslam, from the School of Archaeology at the University of Oxford, said: 'Until now, the only archaeological record of pre-modern, non-human animal tool use comes from a study of three chimpanzee sites in Cote d’Ivoire in Africa, where tools were dated to between 4,300 and 1,300 years old. Here, we have new evidence that suggests monkeys and other primates out of Africa were also using tools for hundreds, possibly thousands of years. This is an exciting, unexplored area of scientific study that may even tell us about the possible influence of monkeys’ tool use on human behavior. For example, cashew nuts are native to this area of Brazil, and it is possible that the first humans to arrive here learned about this unknown food through watching the monkeys and their primate cashew-processing industry.'

Such a world has been discovered by a team of astronomers led by the University of Arizona in Tucson, Arizona, using direct imaging. The planet, HD 131399Ab, is unlike any other known world - on by far the widest known orbit within a multi-star system. The discovery will be published online by the journal Science on Thursday, 7 July, 2016.

Located about 340 light years from Earth in the constellation Centaurus, HD 131399Ab is believed to be about 16 million years old, making it one of the youngest exoplanets discovered to date, and one of very few directly imaged planets. With a temperature of 850 Kelvin (about 1,070 degrees Fahrenheit or 580 degrees Celsius) and weighing in at an estimated four Jupiter masses, it is also one of the coldest and least massive directly imaged exoplanets.

"HD 131399Ab is one of the few exoplanets that have been directly imaged, and it's the first one in such an interesting dynamical configuration," said Daniel Apai, an assistant professor of Astronomy and Planetary Sciences who leads a research group dedicated to finding and observing exoplanets at the UA.

In the Canary Islands, the language called Silbo Gomero is a unique whistled form of Castilian Spanish.

How do you communicate over large distances on a mountainous island full of deep ravines? On La Gomera in the Canaries, inhabitants developed a whistling language to save themselves long and arduous treks. Maybe we should all use it rather than reaching for our mobiles – especially as mountainous areas often have poor network coverage!

The whistling mimics the sounds of the local language, using variations in the notes to represent words. Indeed, brain scans show that listeners are exploiting the same parts of the brain used in normal language processing when interpretting the whistling.

Although other places in the world have whistling languages, this one is unusual because it is so sophisticated and practised by thousands of inhabitants. Indeed, the island habitants learn the language at school. It’s importance has been recognized by Unesco.

One slice through the map of the large-scale structure of the Universe from the Sloan Digital Sky Survey and its Baryon Oscillation Spectroscopic Survey. Each

A team of hundreds of physicists and astronomers have announced results from the largest-ever, three-dimensional map of distant galaxies, created to make one of the most precise measurements yet of the dark energy currently driving the accelerated expansion of the Universe.

“We have spent five years collecting measurements of 1.2 million galaxies over one quarter of the sky to map out the structure of the Universe over a volume of 650 cubic billion light years,” says Jeremy Tinker of New York University, a co-leader of the scientific team carrying out this effort. “This map has allowed us to make the best measurements yet of the effects of dark energy in the expansion of the Universe.”

These new measurements were carried out by the Baryon Oscillation Spectroscopic Survey (BOSS) program of the Sloan Digital Sky Survey-III. Shaped by a continuous tug-of-war between dark matter and dark energy, the map revealed by BOSS allows scientists to measure the expansion rate of the Universe and thus determine the amount of matter and dark energy that make up the present-day Universe. A collection of papers describing these results was submitted this week to the Monthly Notices of the Royal Astronomical Society.

BOSS measures the expansion rate of the Universe by determining the size of the baryonic acoustic oscillations (BAO) in the three-dimensional distribution of galaxies. The original BAO size is determined by pressure waves that traveled through the young Universe up to when it was only 400,000 years old (the Universe is presently 13.8 billion years old), at which point they became frozen in the matter distribution of the Universe.

The end result is that galaxies have a slight preference to be separated by a characteristic distance that astronomers call the acoustic scale. The size of the acoustic scale at 13.7996 billion years ago has been exquisitely determined from observations of the cosmic microwave background from the light emitted when the pressure waves became frozen. Measuring the distribution of galaxies since that time allows astronomers to measure how dark matter and dark energy have competed to govern the rate of expansion of the Universe.

“We’ve made the largest map for studying the 95% of the universe that is dark,” noted David Schlegel, an astrophysicist at Lawrence Berkeley National Laboratory (Berkeley Lab) and principal investigator for BOSS. “In this map, we can see galaxies being gravitationally pulled towards other galaxies by dark matter. And on much larger scales, we see the effect of dark energy ripping the universe apart.”

Birds are remarkably intelligent, although their brains are small. Corvids and some parrots are capable of cognitive feats comparable to those of great apes. How do birds achieve impressive cognitive prowess with walnut-sized brains? Scientists now investigated the cellular composition of the brains of 28 avian species, uncovering a straightforward solution to the puzzle: brains of songbirds and parrots contain very large numbers of neurons, at neuronal densities considerably exceeding those found in mammals. Because these “extra” neurons are predominantly located in the forebrain, large parrots and corvids have the same or greater forebrain neuron counts as monkeys with much larger brains. Avian brains thus have the potential to provide much higher “cognitive power” per unit mass than do mammalian brains.

As the name suggests, these remarkable 3D-printed objects seem to change shape depending on their orientation. "People see it as a circle or as kind of a diamond — in reality, that structure is neither of those things," Sekuler said. "It's a shape that was created so that from a particular perspective you'll see it as one thing or another."

And because the two shapes are so different, it's difficult for people's brains to combine them, she added.

"It makes more sense to say there are two different objects," Sekuler said. "It sounds almost counterintuitive … in this case, the simplicity that's winning out is our familiarity with those shapes."

The researcher, Kokichi Sugihara of Meiji University in Japan, used ambiguous shapes and perspective to craft an illusion that was named a 2015 finalist and one that was a 2010 winner.

In an advance that helps pave the way for next-generation electronics and computing technologies—and possibly paper-thin gadgets —scientists with the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) developed a way to chemically assemble transistors and circuits that are only a few atoms thick.

What's more, their method yields functional structures at a scale large enough to begin thinking about real-world applications and commercial scalability. They report their research online July 11 in the journal Nature Nanotechnology.

The scientists controlled the synthesis of a transistor in which narrow channels were etched onto conducting graphene, and a semiconducting material called a transition-metal dichalcogenide, or TMDC, was seeded in the blank channels. Both of these materials are single-layered crystals and atomically thin, so the two-part assembly yielded electronic structures that are essentially two-dimensional. In addition, the synthesis is able to cover an area a few centimeters long and a few millimeters wide.

"This is a big step toward a scalable and repeatable way to build atomically thin electronics or pack more computing power in a smaller area," says Xiang Zhang, a senior scientist in Berkeley Lab's Materials Sciences Division who led the study.

Researchers are nearing success with designing viruses that attack cancer cells directly.

In 1951, a 4-year-old boy with leukemia contracted chickenpox. His liver and spleen, swollen by the cancer, soon returned to normal, and his elevated blood cell count fell to that of a healthy child. His doctors at the Laboratory of Experimental Oncology in San Francisco were thrilled by his sudden remission, but the blessing was short-lived. After one month, his leukemia returned and progressed rapidly until the child’s death.

In the early 1900s, not much could be done for cancer patients. Unless surgeons could excise a tumor, the disease typically spelled a swift and inevitable end. But in dozens of published cases over the years, doctors noticed a peculiar trend: Struggling cancer patients sometimes enjoyed a brief reprieve from their malignancies when they caught a viral infection. It was not a coincidence. Common viruses sometimes attack tumor cells, researchers discovered. For decades, they tried to harness this phenomenon, to transform it into a cancer treatment. Now, after a long string of failures, they are nearing success with viruses engineered to kill cancer.

“It’s a very exciting time,” said Dr. Robert Martuza, chief neurosurgeon at the Massachusetts General Hospital and professor of neuroscience at Harvard Medical School. “I think it will work out in some tumor, with some virus.” Candidates are already in advanced trials, he noted. Cancer cells are able to replicate wildly, but there’s a trade-off: They cannot ward off infection as effectively as healthy cells. So scientists have been looking for ways to create viruses that are too weak to damage healthy cells yet strong enough to invade and destroy tumor cells. It has been a long, difficult challenge.

Researchers started down this road in 1904, when they discovered that women with cervical cancer temporarily recovered when given a rabies vaccination. By midcentury, physicians were administering live viruses to cancer patients. They tried infecting terminally ill children with polio and adenovirus. They injected patients with concoctions from the feces of normal children, from sick chickens, and from “feline spleen suspension” of rural kittens infected with “cat plague.” These experiments proved ill fated. The cancer returned, or — in the worst cases — the injections themselves caused “the development of lethal infection in the host,” according to a 1964 American Journal of Pathology report. The field was abandoned for a time. But in 1991, Dr. Martuza seized upon the idea of using the herpes simplex virus (HSV-1) as a cancer-fighter.

The genome of HSV-1 is comparatively large and can accommodate a number of mutations and deletions. Dr. Martuza weakened the virus by removing some of its genes. The modified virus was injected into mice with brain cancer, and it did bring about remission. But most of the mice died of encephalitis.

In 1990, Bernard Roizman, a virologist at the University of Chicago, found a “master gene” in the herpes virus. When this gene is removed, the virus no longer has the strength to overcome healthy cells’ defenses. As it turned out, the modified virus was so crippled that it could only slow tumor growth. Then, in 1996, Dr. Ian Mohr, a virologist at New York University, stumbled on a way of further altering Dr. Roizman’s crippled virus. He exposed it repeatedly to cancer cells until a new viral mutant evolved with the ability to replicate in those cells.

Dr. Mohr and a doctoral student, Matt Mulvey, then engineered a way for their virus to evade the immune system, making it an even more potent cancer-killing agent. Unlike chemotherapy, which can diminish in effectiveness over time, oncolytic viruses multiply in the body and gain strength as the infection becomes established. In addition to attacking cancer cells directly, some also produce an immune response that targets tumors.

Today, several potential cancer-fighting viruses are in trials, including two in Phase 3 trials. An engineered form of vaccinia — the viral agent that helped eradicate smallpox — is being tested against advanced liver cancer, the third leading cause of cancer deaths globally. In a recent trial, survival for patients treated with high doses of the virus, called JX-594, doubled to 14 months from 7, compared with that of patients treated with low doses. “To see that kind of response in a randomized trial is simply unheard of,” said Tony Reid, the director of clinical investigation at the Moores Cancer Center of the University of California, San Diego, who has no financial ties to the virus’s manufacturer.

What are epigenetic modifications, and how might they play out across generations?