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Scooped by Dr. Stefan Gruenwald!

A detailed map of Jupiter's moon Ganymede, which might be habitable one day

A detailed map of Jupiter's moon Ganymede, which might be habitable one day | Amazing Science |

One day, poor planet Earth will succumb to the centuries of abuse we've dealt her, shrivel up, and cease to support life. Then, if we're not already living in some Elysium-like habitat in space, we'll have to find a new home. Jupiter's moon, Ganymede, might just be it.

Ganymede with its underground ocean and rocky terrain is already being eyed by scientists as one of the solar system's few habitable environments. Until now, though, we haven't known exactly what was on that far away satellite which also happens to be the largest moon in our solar system. Thankfully, a team of Brown scientists and geologists fixed that problem by making this terrifically detailed map of Ganymede using images from NASA's Voyager and Galileo missions.

The map is a little intimidating at first, but once you delve into it, you'll realize that exploring the geography of Ganymede isn't so different from exploring the geography of Earth. Different colors represent the different elements that make up the moon's surface creating an almost marbled look as the minerals run together. Of course, Ganymede would need a little work before we can colonize it. But let's just hope we never have to.

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Microrobotic technique combines 3D printing and tissue engineering

Microrobotic technique combines 3D printing and tissue engineering | Amazing Science |

Researchers at Brigham and Women's Hospital (BWH) and Carnegie Mellon University have introduced a unique micro-robotic technique to assemble the components of complex materials, the foundation of tissue engineering and 3D printing, described in the Jan. 28, 2014, issue of Nature Communications ("Untethered micro-robotic coding of three-dimensional material composition").

Tissue engineering and 3D printing have become vitally important to the future of medicine for many reasons. The shortage of available organs for transplantation, for example, leaves many patients on lengthy waiting lists for life-saving treatment. Being able to engineer organs using a patient's own cells can not only alleviate this shortage, but also address issues related to rejection of donated organs. Developing therapies and testing drugs using current preclinical models have limitations in reliability and predictability. Tissue engineering provides a more practical means for researchers to study cell behavior, such as cancer cell resistance to therapy, and test new drugs or combinations of drugs to treat many diseases.

The presented approach uses untethered magnetic micro-robotic coding for precise construction of individual cell-encapsulating hydrogels (such as cell blocks). The micro-robot, which is remotely controlled by magnetic fields, can move one hydrogel at a time to build structures. This is critical in tissue engineering, as human tissue architecture is complex, with different types of cells at various levels and locations. When building these structures, the location of the cells is significant in that it will impact how the structure will ultimately function. "Compared with earlier techniques, this technology enables true control over bottom-up tissue engineering," explains Tasoglu.

Tasoglu and Demirci also demonstrated that micro-robotic construction of cell-encapsulating hydrogels can be performed without affecting cell vitality and proliferation. Further benefits may be realized by using numerous micro-robots together in bioprinting, the creation of a design that can be utilized by a bioprinter to generate tissue and other complex materials in the laboratory environment."

Our work will revolutionize three-dimensional precise assembly of complex and heterogeneous tissue engineering building blocks and serve to improve complexity and understanding of tissue engineering systems," said Metin Sitti, professor of Mechanical Engineering and the Robotics Institute and head of CMU's NanoRobotics Lab.

"We are really just beginning to explore the many possibilities in using this micro-robotic technique to manipulate individual cells or cell-encapsulating building blocks." says Demirci. "This is a very exciting and rapidly evolving field that holds a lot of promise in medicine."

Deborah Verran's curator insight, February 14, 2014 10:07 PM

Another interesting step in the research that is being performed in the tissue engineering sphere. However there is a lot more research required before bioengineered tissues can be used for transplantation into humans

Sieg Holle's curator insight, February 16, 2014 11:23 AM

Towards our age of abundance and self sufficiency and personal choice?

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Lockheed Martin joins the world's largest wave-energy development project

Lockheed Martin joins the world's largest wave-energy development project | Amazing Science |

Lockheed Martin has joined a partnership to develop what it described as “the world’s largest wave energy project” to date, off the Victoria coast in southern Australia. Victorian Wave Partners Ltd. is an Australian special-purpose company owned by Ocean Power Technologies Australasia Pty Ltd., a developer of “wave energy” technology.

OPT’s PowerBuoy system uses a "smart" buoy to convert wave energy into electricity.  The buoy moves up and down with the rising and falling of waves, and the mechanical energy generated by this action drives an electrical generator, which transmits power to shore via an underwater cable.

The system is designed to be electrically tuned on a wave-by-wave basis to maximize the amount of electricity produced. In the Australian development, anticipated peak-power generating capacity is 62.5 megawatts. That would be sufficient to supply 10,000 homes.

The Victorian Wave project is scheduled to be built in three stages, with the first stage producing approximately 2.5 megawatts of peak power.

No starting date has been indicated for the installation.

Lockheed did not reveal the value of its investment.  It will provide overall project management, assist with the design for manufacturing the PowerBuoy systems, lead the production of selected components, and perform system integration of the wave energy converters.

Lockheed Martin’s participation in this project is reminiscent of Boeing’s recent participation in a tidal-energy project, though wave power is distinct from tidal power.

Wave power devices extract energy from the surface motion of ocean waves, which is very predictable and reportedly will generate electricity for more hours in a year than wind and solar sources.

"We are applying our design and system integration expertise to commercialize promising, emerging alternative energy technologies, including ocean power," stated Tim Fuhr, director of ocean energy for Lockheed Martin's Mission Systems and Training business. "This project extends our established relationship with OPT and Australian industry, and enables us to demonstrate a clean, efficient energy source for Australia and the world."

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Predictable Lifespan: Worm Study Suggests that Mitochondrial Activity Determines Aging

Predictable Lifespan: Worm Study Suggests that Mitochondrial Activity Determines Aging | Amazing Science |

Scientists have a crystal ball on their hands: bursts of activity in the energy-producing mitochondria in a worm’s cells accurately predict how long it will live. The findings, published in Nature1, suggest that an organism’s lifespan is, for the most part, predictable in early adulthood. Unlike other biomarkers for aging, which work under limited conditions, these mitochondrial bursts are a stable predictor for a variety of genetic, environmental and developmental histories.

“Mitochondrial flashes have an amazing power to predict the remaining lifespan in animals,” says study lead Meng-Qiu Dong, a geneticist who studies aging in the Caenorhabditis elegans worm at the National Institute of Biological Sciences in Beijing. “There is truth in the mitochondrial theory of aging.”

The mitochondria are organelles that power the cells of plants, animals and other eukaryotic organisms. During energy production, they produce reactive oxygen molecules, such as free radicals, that can cause stress and damage the mitochondria. Although mitochondria break down over time, the mitochondrial theory of aging, first proposed2 in 1972, remains controversial and unproven. For instance, some long-lived organisms, such as naked mole rats, endure with high levels of oxidative damage. Nevertheless, many scientists think that mitochondria remain the primary drivers of aging.

Dong became interested in the 2008 discovery3 that mitochondria produce reactive oxygen molecules in 10-second pulses — ‘mitoflashes’ — every couple minutes. For the first time, scientists could observe individual mitochondria and their rates of activity through the course of an animal’s life. In this study, Dong initially compared mitoflash rates in short-lived C. elegans worms, which live an average of 21 days, to long-lived worms that live an average of 30 days or more. She found that, in all of the animals, there were two moments in life when mitoflashes bunched closely together: one burst during early adulthood and another during senescence.

At first, she expected that the burst later in life would be the important one. “It was a total failure,” she says. Instead, it was the early burst that revealed a correlation between flash frequency and lifespan: worms with an average lifespan of 21 days had more frequent flashes during this burst than their longer-lived brethren. The correlation held across 29 genetic mutants with various lifespans. Mitoflashes also proved to be a powerful record of a worm’s early life experiences. For instance, worms exposed to heat shock or starvation tend to have longer lives, and predictably, their mitoflashes occurred at longer intervals. Even genetically identical worms that had different lifespans due to chance events alone showed the same correlation between mitoflash frequency and longevity. The most striking finding came when Dong treated a long-lived worm to increase its production of reactive oxygen molecules. This shortened the worm’s life and increased the rate of mitoflashes.

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Scientists Say Their Giant Laser Has For The First Time Produced Nuclear Fusion

Scientists Say Their Giant Laser Has For The First Time Produced Nuclear Fusion | Amazing Science |

Researchers at a laboratory in California say they've had a breakthrough in producing fusion power with a giant laser. The success comes after years of struggling to get the laser to work, and is another step in the decades-long quest for fusion energy. Omar Hurricane, a researcher at Lawrence Livermore National Laboratory, says that for the first time, they've produced significant amounts of fusion by zapping a target with their laser. "We've gotten more energy out of the fusion fuel than we put into the fusion fuel," he says.

Strictly speaking, while more energy came from fusion than went into the hydrogen fuel, only about 1 percent of the laser's energy ever reached the fuel. Useful levels of fusion are still a long way off. "They didn't get more fusion power out than they put in with the laser," says Steve Cowley, the head of a huge fusion experiment in the U.K. called the Joint European Torus, or JET.

The laser is known as the National Ignition Facility, or NIF. Constructed at a cost of more than $3 billion, it consists of 192 beams that take up the length of three football fields. For a brief moment, the beams can focus 500 trillion watts of power — more power than is being used in that same time across the entire United States — onto a target about the width of a No. 2 pencil.

The goal is fusion. Fusion is a process where hydrogen atoms are squeezed together to make helium atoms. When that happens, a lot of energy comes out. It could mean the answer to the world's energy problems, but fusion is really, really hard to do. Hurricane says that each time they try, it feels like they're taking a test.

"Of course you want to score real well, you think you've learned the material, but you just have to see how you do," he says.

Over the past few years, NIF has been getting a fat "F." For all its power, it just couldn't get the hydrogen to fuse, and researchers didn't know why. The failures have led NIF's critics to label the facility an enormous waste of taxpayer dollars. In 2012, the government shifted NIF away from its fusion goals to focus on its other mission: simulating the conditions inside nuclear weapons.

But the fusion experiments continued, and Hurricane says researchers now understand why their original strategy wasn't working. In the journal Nature, he and his colleagues report that they've finally figured out how to squeeze the fuel with the lasers. By doing a lot of squeezing right at the start, they were able to keep the fuel from churning and squirting out. The lasers squeezed evenly and the hydrogen turned into helium. The new technique can't reach "ignition," which is the point at which the hydrogen fusion feeds on itself to make more. Even so, JET's Cowley says, this is still a big moment for NIF.

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Truncated guide RNAs drastically improve specificity of CRISPR-Cas nucleases

Truncated guide RNAs drastically improve specificity of CRISPR-Cas nucleases | Amazing Science |
A simple adjustment to a powerful gene-editing tool may be able to improve its specificity. Investigators have found that adjusting the length of the the guide RNA component of the synthetic enzymes called CRISPR-Cas RNA-guided nucleases can substantially reduce the occurrence of off-target DNA mutations.

Clustered, regularly interspaced, short palindromic repeat (CRISPR) RNA-guided nucleases (RGNs) are highly efficient genome editing tools123. CRISPR-associated 9 (Cas9) RGNs are directed to genomic loci by guide RNAs (gRNAs) containing 20 nucleotides that are complementary to a target DNA sequence. However, RGNs can induce mutations at sites that differ by as many as five nucleotides from the intended target456. A research team recently reports that truncated gRNAs, with shorter regions of target complementarity <20 nucleotides in length, can decrease undesired mutagenesis at some off-target sites by 5,000-fold or more without sacrificing on-target genome editing efficiencies. In addition, use of truncated gRNAs can further reduce off-target effects induced by pairs of Cas9 variants that nick DNA (paired nickases). These results delineate a simple, effective strategy to improve the specificities of Cas9 nucleases or paired nickases.

"Simply by shortening the length of the gRNA targeting region, we saw reductions in the frequencies of unwanted mutations at all of the previously known off-target sites we examined," says J. Keith Joung, MD, PhD, associate chief for Research in the MGH Department of Pathology and senior author of the report. "Some sites showed decreases in mutation frequency of 5,000-fold or more, compared with full length gRNAs, and importantly these truncated gRNAs -- which we call tru-gRNAs -- are just as efficient as full-length gRNAs at reaching their intended target DNA segments."

CRISPR-Cas RGNs combine a gene-cutting enzyme called Cas9 with a short RNA segment and are used to induce breaks in a complementary DNA segment in order to introduce genetic changes. Last year Joung's team reported finding that, in human cells, CRISPR-Cas RGNs could also cause mutations in DNA sequences with differences of up to five nucleotides from the target, which could seriously limit the proteins' clinical usefulness. The team followed up those findings by investigating a hypothesis that could seem counterintuitive, that shortening the gRNA segment might reduce off-target mutations.

"Some of our experiments from last year suggested that one could mismatch a few nucleotides at one end of the gRNA complementarity region without affecting the targeting activity," Joung explains. "That led us to wonder whether removing these nucleotides could make the system more sensitive to mismatches in the remaining sequence."

Based on a natural system a species of bacteria uses against other pathogens, the CRISPR-Cas RGNs most widely used by researchers includes a 20-nucleotide targeting region within the gRNA. To test their theory, the MGH team constructed RGNs with progressively shorter gRNAs and found that, while gRNAs with targeting segments of 17 or 18 nucleotides were as or more efficient than full-length gRNAs in reaching their targets, those with 15- or 16-nucleotide targeting segments had reduced or no targeting activity. Subsequent experiments found that 17-nucleotide truncated RGNs efficiently induced the desired mutations in human cells with greatly reduced or undetectable off-target effects, even at sites with only one or two mismatches.

"While we don't fully understand the mechanism by which tru-gRNAs reduce off-target effects, our hypothesis is that the original system might have more energy than it needs, enabling it to cleave even imperfectly matched sites," says Joung, who is an associate professor of Pathology at Harvard Medical School. "By shortening the gRNA, we may reduce the energy to a level just sufficient for on-target activity, making the nuclease less able to cleave off-target sites. But more work is needed to define exactly why tru-gRNAs have reduced off-target effects."

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Wobbly Alien Planet with Wild Seasons Found by NASA Telescope

Wobbly Alien Planet with Wild Seasons Found by NASA Telescope | Amazing Science |

Astronomers have discovered an alien planet that wobbles at such a dizzying rate that its seasons must fluctuate wildly. Throughout all of the planet's fast-changing seasons, however, no forecast would be friendly to humans. The warm planet is a gassy super-Neptune that orbits too close to its two parent stars to be in its system's "habitable zone," the region where temperatures would allow liquid water, and perhaps life as we know it, to exist.

The faraway world, which lies 2,300 light-years away in the constellation Cygnus, was discovered by NASA's planet-hunting Kepler space telescope. Dubbed Kepler-413b, the planet orbits a pair of orange and red dwarf stars every 66 days. [A World of Kepler Planets]

Kepler was designed to detect exoplanets by noticing the dips in brightness caused when these worlds transit, or cross in front of, their parent stars. Normally these transits occur in a regular pattern, but Kepler-413b behaved strangely.

"What we see in the Kepler data over 1,500 days is three transits in the first 180 days (one transit every 66 days), then we had 800 days with no transits at all," study lead investigator Veselin Kostov, of the Space Telescope Science Institute and Johns Hopkins University, said in a statement. "After that, we saw five more transits in a row."

Kostov and colleagues concluded that the planet's wobble must be causing it to move up or down relative to our view, so much so that it sometimes doesn't appear to cross in front of its parent stars. A NASA statement compared the planet's motions to a child's spinning top on the rim of a wobbling bicycle wheel rotating on its side.

The scientists determined that the planet's axial tilt can vary by as much as 30 degrees over 11 years,. For comparison, Earth's tilt has shifted 23.5 degrees over 26,000 years. The researchers say it's amazing that this planet is wobbling, or precessesing, so much on a human time scale, and they say it's possible that there are other planets like Kepler-413b awaiting discovery.

"Presumably there are planets out there like this one that we're not seeing because we're in the unfavorable period," Peter McCullough, a team member from STScI and JHU, said in a statement.

Kostov and colleagues are still investigating what causes the extreme wobble of the gas planet, which has a mass about 65 times that of Earth. They say Kepler-413b's orbit may have been tilted by other planets in the system or by a nearby star exerting gravitational influence.

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New study examines thousands of brains to reveal differences between male and female brain structure

New study examines thousands of brains to reveal differences between male and female brain structure | Amazing Science |

Reviewing over 20 years of neuroscience research into sex differences in brain structure, a Cambridge University team has conducted the first meta-analysis of the evidence, published this week in the prestigious journal Neuroscience and Biobehavioral Reviews

The team, led by doctoral candidate Amber Ruigrok and Professors John Suckling and Simon Baron-Cohen in the Department of Psychiatry, performed a quantitative review of the brain imaging literature testing overall sex differences in total and regional brain volumes. They searched all articles published between 1990 and 2013. A total of 126 articles were included in the study, covering brains from individuals as young as birth to 80 years old.

They found that males on average have larger total brain volumes than women (by 8-13%). On average, males had larger absolute volumes than females in the intracranial space (12%; >14,000 brains), total brain (11%; 2,523 brains), cerebrum (10%; 1,851 brains), grey matter (9%; 7,934 brains), white matter (13%; 7,515 brains), regions filled with cerebrospinal fluid (11.5%; 4,484 brains), and cerebellum (9%; 1,842 brains). Looking more closely, differences in volume between the sexes were located in several regions. These included parts of the limbic system, and the language system.

Specifically, males on average had larger volumes and higher tissue densities in the left amygdala, hippocampus, insular cortex, putamen; higher densities in the right VI lobe of the cerebellum and in the left claustrum; and larger volumes in the bilateral anterior parahippocampal gyri, posterior cingulate gyri, precuneus, temporal poles, and cerebellum, areas in the left posterior and anterior cingulate gyri, and in the right amygdala, hippocampus, and putamen.

By contrast, females on average had higher density in the left frontal pole, and larger volumes in the right frontal pole, inferior and middle frontal gyri, pars triangularis, planum temporale/parietal operculum, anterior cingulate gyrus, insular cortex, and Heschl’s gyrus; bilateral thalami and precuneus; the left parahippocampal gyrus, and lateral occipital cortex.

The results highlight an asymmetric effect of sex on the developing brain. Amber Ruigrok, who carried out the study as part of her PhD, said: “For the first time we can look across the vast literature and confirm that brain size and structure are different in males and females. We should no longer ignore sex in neuroscience research, especially when investigating psychiatric conditions that are more prevalent in either males or females.”

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First map of core white-matter connections of human brain developed

First map of core white-matter connections of human brain developed | Amazing Science |

USC neuroscientists have systematically created the first map of the core white-matter “scaffold” (connections) of the human brain — the critical communications network that supports brain function. Their work, published Feb. 11, 2014 in the open-access journal Frontiers in Human Neuroscience, has major implications for understanding brain injury and disease, the researchers say.

By detailing the connections that have the greatest influence over all other connections, the researchers offer a landmark first map of core white matter pathways and also show which connections may be most vulnerable to damage.

“We coined the term white matter ‘scaffold’ because this network defines the information architecture which supports brain function,” said senior author John Darrell Van Horn of the USC Institute for Neuroimaging and Informatics and the Laboratory of NeuroImaging.

“While all connections in the brain have their importance, there are particular links which are the major players,” Van Horn said.

Using MRI data from a large sample of 110 individuals, lead author Andrei Irimia, also of the USC Institute for Neuroimaging and Informatics, and Van Horn systematically simulated the effects of damaging each white matter pathway.

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Searching space dust for minute quantities of life’s ingredients

Searching space dust for minute quantities of life’s ingredients | Amazing Science |

Goddard Astrobiology Analytical Laboratory scientists have applied advanced technology to inspect extremely small meteorite samples for the components of life. “We found amino acids in a 360 microgram sample of the Murchison meteorite,” said Callahan. “This sample size is 1,000 times smaller than the typical sample size used. “We got the same results looking at a very small fragment as we did a much larger fragment from the same meteorite.”

Callahan said these techniques will allow the scientists  to investigate other small-scale extraterrestrial materials such as micrometeorites, interplanetary dust particles, and cometary particles in future studies.

The team used a nanoflow liquid chromatography instrument to sort the molecules in the meteorite sample, then applied nanoelectrospray ionization to give the molecules an electric charge and deliver them to a high-resolution mass spectrometer instrument, which identified the molecules based on their mass. “We are pioneering the application of these techniques for the study of meteoritic organics,” said Callahan.

This technology and the laboratory techniques that the Goddard lab develops to apply it to analyze meteorites will be valuable for future sample-return missions since the amount of sample likely will be limited.

“Missions involving the collection of extraterrestrial material for sample return to Earth usually collect only a very small amount and the samples themselves can be extremely small as well,” said Callahan.

“The traditional techniques used to study these materials usually involve inorganic or elemental composition. Targeting biologically relevant molecules in these samples is not routine yet. We are not there either, but we are getting there.”

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First monkeys with customized mutations born, promising better models for human genetic diseases

First monkeys with customized mutations born, promising better models for human genetic diseases | Amazing Science |

Twin cynomolgus monkeys born in China are the first with mutations in specific target genes. This is an important milestone for targeted gene-editing technology, which in turn promises better models for human diseases.

The ultimate potential of precision gene-editing techniques is beginning to be realized. Today, researchers in China report the first monkeys engineered with targeted mutations1, an achievement that could be a stepping stone to making more realistic research models of human diseases.

Xingxu Huang, a geneticist at the Model Animal Research Center of Nanjing University in China, and his colleagues successfully engineered twin cynomolgus monkeys (Macaca fascicularis) with two targeted mutations using the CRISPR/Cas9 system — a technology that has taken the field of genetic engineering by storm in the past year. Researchers have leveraged the technique to disrupt genes in mice and rats23, but until now none had succeeded in primates.

Transgenic mice have long dominated as models for human diseases, in part because scientists have honed a gene-editing method for the animals that uses homologous recombination — rare, spontaneous DNA-swapping events — to introduce mutations. The strategy works because mice reproduce quickly and in large numbers, but the low rates of homologous recombination make such a method unfeasible in creatures such as monkeys, which reproduce slowly.

"We need some non-human primate models," says Hideyuki Okano, a stem-cell biologist at Keio University in Tokyo. Human neuropsychiatric disorders can be particularly difficult to replicate in the simple nervous systems of mice, he says.

Stem-cell researcher Rudolf Jaenisch of the Whitehead Institute for Biomedical Research in Cambridge, Massachusetts, calls the result an interesting demonstration, but says that it offers little scientific insight. "The next step is to see if we can learn anything from it," says Jaenisch, who pioneered the use of transgenic mice in the 1970s.

The combined mutations in Ppar-γ and Rag1 do not represent a particular disease syndrome, says Huang, although each gene is associated with human disorders.The group has yet to fully analyze the monkeys' condition, and must run further tests to assess whether the mutations occurred in all of the animals' cells."Our first aim was to get it done, to get it to work," Huang says. But the finding suggests that researchers could one day model other human conditions involving multiple mutations.

The race is already on to create more CRISPR-modified monkeys, and with greater reliability. Zhang and his colleagues are working to optimize the technology for primate cells, in order to boost mutation efficiency. Okano's team is analyzing unpublished results from monkey models of autism and immune dysfunction, recently created with older gene-editing technologies; they, too, are now trying their luck with CRISPR. And Huang's group is expecting results from eight other pending pregnancies. "There are a lot more things to do," says Huang.

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The choosy uterus: New insight into why embryos often do not implant

The choosy uterus: New insight into why embryos often do not implant | Amazing Science |

Fertility experts at the University of Southampton and University of Warwick have found new insights into why some fertilized eggs can embed in a uterus and why some do not. Led by Nick Macklon, Professor of Gynaecology and Obstetrics at the University of Southampton and Professor Jan Brosens at the University of Warwick, the research has shown that if the embryo quality is poor, the endometrium will subdue a large number of the genes involved in determining whether the embryo is accepted.

Human embryos frequently harbor large-scale complex chromosomal errors that impede normal development. Affected embryos may fail to implant although many first breach the endometrial epithelium and embed in the decidualizing stroma before being rejected via mechanisms that are still poorly understood. A group of researchers now show that developmentally impaired human embryos elicit an endoplasmic stress response in human decidual cells. A stress response was also evident upon in vivo exposure of mouse uteri to culture medium conditioned by low-quality human embryos.

By contrast, signals emanating from developmentally competent embryos activated a focused gene network enriched in metabolic enzymes and implantation factors. The further show that trypsin, a serine protease released by pre-implantation embryos, elicits Ca2+ signaling in endometrial epithelial cells. Competent human embryos triggered short-lived oscillatory Ca2+ fluxes whereas low-quality embryos caused a heightened and prolonged Ca2+ response. Thus, distinct positive and negative mechanisms contribute to active selection of human embryos at implantation.

Professor Macklon comments: “Our research has shown that one of the signals which the uterus can pick up on in determining the quality of the embryo is the amount of trypsin it gives off. The lack of trypsin signals appear to indicate to the endometrium that the embryo’s quality is not very high and initiates a reduction in receptivity to implantation.”

It is hoped the discovery will open new avenues to develop new techniques to improve the success rate of IVF. Professor Macklon adds: “One in six couples will experience some sort of infertility, which can be both frustrating and daunting, and many will turn to IVF.  “But the big problem in IVF is still the low chance of getting embryos to implant. These new insights into how an endometrium chooses an embryo may open new avenues to develop new treatments for this.”

During the study, which also involved the University of Utrecht, the researchers took the fluid in which the embryos had been cultured and incubated it with endometrial stromal cells. They then measured the reaction of the genes in the endometrium. The team found almost no reaction when the media had contained good quality embryos, but a huge reaction when it had contained bad quality embryos. The genes, which were down-regulated, are known to be important in implantation, showing that the uterus can choose the best embryo.

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Advances in Next-Gen Sequencing and Bioinformatics Permit High-Res Single-Cell Genome Sequencing

Advances in Next-Gen Sequencing and Bioinformatics Permit High-Res Single-Cell Genome Sequencing | Amazing Science |

Single-cell Whole Genome Analysis (WGA) has recently been accomplished on a variety of high-throughput platforms, including DNA-microarrays, SNP-arrays, and NGS. A key difficulty in the interpretation of single-cell WGA data on any platform is the separation of the numerous WGA artifacts from the genuine genetic variants present in the template genome.

Standard DNA-microarrays can detect copy number variations (CNVs) larger than 2.5 Mb from a single-cell genome [Ref], while targeted array comparative genomic hybridizations can discover approximately 1 Mb-sized DNA imbalances [Ref], although remarkably, CNVs as small as 56 kb in single-cell PCR-based WGA products have been detected [Ref]. Similarly, SNP-arrays can find copy number aberrations encompassing millions of bases in a cell [Ref], but have the advantage of enabling the discovery of copy neutral DNA anomalies and regions of loss-of-heterozygosity (LOH), and allow inferring genome-wide haplotypes [Ref].

Next Generation Sequencing (NGS) has a number of advantages over microarrays enabling improved resolution and accuracy in variant calling [Ref]. First, NGS can examine every nucleotide amplified from the cell and allows genome-wide discovery of the full spectrum of DNA mutations, while microarrays only probe for certain CNV loci.

Secondly, sequencing provides digital precision, with one digital unit representing a mapped sequence read. Finally, paired-end sequencing and mapping discloses the linkage between both ends of each linear DNA-molecule in a sequencing library of a single-cell WGA product, allowing the identification of structural variations via read-pairs mapping discordantly to the reference genome.

Analytical challenges remain in interpreting single-cell NGS data for the full spectrum of genetic variants. Although WGA imperfections due to genome base composition (e.g. %GC-bias) can be computationally corrected for [Ref]. Allelic fractions of heterozygous SNPs [Ref] or aberrantly mapping read pairs following paired-end sequencing of the WGA product [Ref] can be used to increase confidence in CNV measurements. For instance, a real deletion of a diploid locus should show LOH and discordantly mapping read-pairs that explain the DNA loss. Furthermore, the cell cycle stage of the isolated cell must be considered, further complicating the analysis, as cells in S-phase demonstrate a dynamic copy number profile, leading to false structural DNA-imbalance discoveries [Ref].

The identification of the full spectrum of intra- and inter-chromosomal (un)balanced structural variants in a single-cell WGA product is still in its infancy—the main difficulty being to filter true structural variants from chimeric DNA generated during WGA, as well as issues with genome coverage. Although filters have been designed to permit the detection of the structural architecture of DNA copy number variation and even to detect L1-retro-transposition [Ref], many structural variants are still missed in single-cell analyses.

Despite these hurdles, several groups have proven the efficacy of single-cell NGS to detect multiple classes of mutation within a genome and even to detect sister chromatid exchanges following single-cell Strand-seq [Ref]. Step-by-step bioinformatics protocols for analyzing Strand-seq data as well as for copy number profiling single cells through NGS or microarray analysis and commercial solutions (e.g. platforms used within are surfacing.[Ref]

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Out of this world first light images emerge as the Gemini Planet Imager in Chile goes online

Out of this world first light images emerge as the Gemini Planet Imager in Chile goes online | Amazing Science |

After nearly a decade of development, construction and testing, the world's most advanced instrument for directly imaging and analyzing planets orbiting around other stars is pointing skyward and collecting light from distant worlds. 

"Even these early first-light images are almost a factor of 10 better than the previous generation of instruments. In one minute, we were seeing planets that used to take us an hour to detect," says Bruce Macintosh of Lawrence Livermore National Laboratory, who led the team who built the instrument. 

For the past decade, Lawrence Livermore has been leading a multi-institutional team in the design, engineering, building and optimization of the instrument, called the Gemini Planet Imager (GPI), which will be used for high-contrast imaging to better study faint planets or dusty disks next to bright stars. Astronomers -- including a team at LLNL-- have made direct images of a handful of extrasolar planets by adapting astronomical cameras built for other purposes. GPI is the first fully optimized planet imager, designed from the ground up for exoplanet imaging deployed on one of the world's biggest telescopes, the 8-meter Gemini South telescope in Chile.

Gemini Planet Imager's first light image (see picture) of the light scattered by a disk of dust orbiting the young star HR4796A. This narrow ring is thought to be dust from asteroids or comets left behind by planet formation; some scientists have theorized that the sharp edge of the ring is defined by an unseen planet. The left image shows normal light, including both the dust ring and the residual light from the central star scattered by turbulence in the Earth's atmosphere. The right image shows only polarized light. Leftover starlight is unpolarized and hence removed from this image. The light from the back edge of the disk is strongly polarized as it scatters towards us.

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Mechanical Overlords: AI Robots are Infiltrating Insect, Fish and Bird Communities and Take Control

Mechanical Overlords: AI Robots are Infiltrating Insect, Fish and Bird Communities and Take Control | Amazing Science |

Several years ago, a group of American cockroaches discovered four strangers in their midst. A brief investigation revealed that the interlopers smelled like cockroaches, and so they were welcomed into the cockroach community. The newcomers weren’t content to just sit on the sidelines, however. Instead, they began to actively shape the group’s behavior. Nocturnal creatures, cockroaches normally avoid light. But when the intruders headed for a brighter shelter, the rest of the roaches followed.

What the cockroaches didn’t seem to realize was that their new, light-loving leaders weren’t fellow insects at all. They were tiny mobile robots, doused in cockroach pheromones and programmed to trick the living critters into following their lead. The demonstration, dubbed the LEURRE project and conducted by a team of European researchers, validated a radical idea—that robots and animals could be merged into a “biohybrid” society, with biological and technological organisms forming a cohesive unit.

A handful of scientists have now built robots that can socially integrate into animal communities. Their goal is to create machines that not only infiltrate animal groups but also influence them, changing how fish swim, birds fly, and bees care for their young. If the research reaches the real world, we may one day use robots to manage livestock, control pests, and protect and preserve wildlife. So, dear furry and feathered friends, creepy and crawly creatures of the world: Prepare for a robo-takeover.

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Atomic circuits move a step closer – Memory effect seen for the first time in a cloud of ultracold atoms

Atomic circuits move a step closer – Memory effect seen for the first time in a cloud of ultracold atoms | Amazing Science |

A memory effect that is crucial in electronics has been seen for the first time in a cloud of ultracold atoms. The phenomenon represents a milestone in the emerging field of ‘atomtronics’, which seeks to create a whole new class of devices that use the flow of atoms, rather than electrons, in a circuit.

In atomtronics, clouds of atoms are super-cooled to form a collective quantum state known as a Bose-Einstein condensate (BEC). So far, physicists have used these atoms in analogues of basic electrical components such as transistors1and capacitors2. Such condensates can also become a superfluid — meaning atoms can flow past obstacles without friction — and be set in motion, circulating inside a ring-shaped trap.

Atomtronics has so far been largely theoretical, but it holds potential for developing entirely new quantum devices, says Gretchen Campbell, a physicist at the University of Maryland in College Park. Publishing in Nature3, her team is the first to directly see an effect known as hysteresis in an atomtronic circuit. Hysteresis is the dependence of a system not just on its current state, but also on its history.

A thermostat, for example, might turn a heating system off as the temperature rises to 21 °C, but will not turn it on again until it falls below 18 °C. This prevents small disturbances from causing big changes.

Magnetic hard drives, which store data in 0s and 1s, also exploit hysteresis: turning on a magnetic field can turn a 0 into a 1, but you need to do more than just remove the field to reverse the effect. “We don’t yet know exactly what these atomtronic devices would be,” Campbell says. “But in any real circuit you need hysteresis — something that acts like a memory or a filter."

"This work is really interesting, because it puts all the components of atomtronics together, studying collective behaviour of atoms and memory effects," says Shan-Wen Tsai, a physicist at the University of California, Riverside.

Atomtronics will not directly replace electronics, because atomic circuits are slower and bigger than their zippy electron counterparts. "You wouldn’t put a billion atomtronics components on a chip," Tsai adds.

But the atomtronic circuit could be useful in applications such as rotation sensors, playing the part that gyroscopes have in spacecraft and aeroplane navigation. The devices could also some day perform rudimentary quantum computations, says Ludwig Mathey, a theoretical physicist at the University of Hamburg in Germany, who works on simulating ultracold atom systems. Future 'quantum computers' promise to perform certain tasks exponentially faster than any traditional computer ever could. “ BECs have the advantage of being more robust than other kinds of quantum computer,” he says.

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The milk revolution: A single genetic mutation first let ancient Europeans drink milk

The milk revolution: A single genetic mutation first let ancient Europeans drink milk | Amazing Science |

When a single genetic mutation first let ancient Europeans drink milk, it set the stage for a continental upheaval. During the most recent ice age, milk was essentially a toxin to adults because — unlike children — they could not produce the lactase enzyme required to break down lactose, the main sugar in milk. But as farming started to replace hunting and gathering in the Middle East around 11,000 years ago, cattle herders learned how to reduce lactose in dairy products to tolerable levels by fermenting milk to make cheese or yogurt. Several thousand years later, a genetic mutation spread through Europe that gave people the ability to produce lactase — and drink milk — throughout their lives.

Young children almost universally produce lactase and can digest the lactose in their mother's milk. But as they mature, most switch off the lactase gene. Only 35% of the human population can digest lactose beyond the age of about seven or eight (2). “If you're lactose intolerant and you drink half a pint of milk, you're going to be really ill.

Most people who retain the ability to digest milk can trace their ancestry to Europe, where the trait seems to be linked to a single nucleotide in which the DNA base cytosine changed to thymine in a genomic region not far from the lactase gene. There are other pockets of lactase persistence in West Africa (see Nature 444994996; 2006), the Middle East and south Asia that seem to be linked to separate mutations3 (so called 'Lactase hotspots').

The single-nucleotide switch in Europe happened relatively recently. Thomas and his colleagues estimated the timing by looking at genetic variations in modern populations and running computer simulations of how the related genetic mutation might have spread through ancient populations4. They proposed that the trait of lactase persistence, dubbed the LP allele, emerged about 7,500 years ago in the broad, fertile plains of Hungary.

AckerbauHalle's curator insight, February 13, 2014 1:55 AM

Woher kommt die Fähigkeit zur Verdauung von Laktase? Neue genetische Studien bringen hier Licht ins Dunkel.

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Permian extinction happened within 60,000 years—much faster than previously thought

Permian extinction happened within 60,000 years—much faster than previously thought | Amazing Science |

The largest mass extinction in the history of animal life occurred some 252 million years ago, wiping out more than 96 percent of marine species and 70 percent of life on land—including the largest insects known to have inhabited the Earth. Multiple theories have aimed to explain the cause of what's now known as the end-Permian extinction, including an asteroid impact, massive volcanic eruptions, or a cataclysmic cascade of environmental events. But pinpointing the cause of the extinction requires better measurements of how long the extinction period lasted.

Now researchers at MIT have determined that the end-Permian extinction occurred over 60,000 years, give or take 48,000 years—practically instantaneous, from a geologic perspective. The new timescale is based on more precise dating techniques, and indicates that the most severe extinction in history may have happened more than 10 times faster than scientists had previously thought.

"We've got the extinction nailed in absolute time and duration," says Sam Bowring, the Robert R. Shrock Professor of Earth and Planetary Sciences at MIT. "How do you kill 96 percent of everything that lived in the oceans in tens of thousands of years? It could be that an exceptional extinction requires an exceptional explanation."

In addition to establishing the extinction's duration, Bowring, graduate student Seth Burgess, and a colleague from the Nanjing Institute of Geology and Paleontology also found that, 10,000 years before the die-off, the oceans experienced a pulse of light carbon, which likely reflects a massive addition of carbon dioxide to the atmosphere. This dramatic change may have led to widespread ocean acidification and increased sea temperatures by 10 degrees Celsius or more, killing the majority of sea life.

But what originally triggered the spike in carbon dioxide? The leading theory among geologists and paleontologists has to do with widespread, long-lasting volcanic eruptions from the Siberian Traps, a region of Russia whose steplike hills are a result of repeated eruptions of magma. To determine whether eruptions from the Siberian Traps triggered a massive increase in oceanic carbon dioxide, Burgess and Bowring are using similar dating techniques to establish a timescale for the Permian period's volcanic eruptions that are estimated to have covered over five million cubic kilometers.

The new timeline adds weight to the theory that the extinction was triggered by massive volcanic eruptions from the Siberian Traps that released volatile chemicals, including carbon dioxide, into the atmosphere and oceans. With such a short extinction timeline, Bowring says it is possible that a single, catastrophic pulse of magmatic activity triggered an almost instantaneous collapse of all global ecosystems.

To confirm whether the Siberian Traps are indeed the extinction's smoking gun, Burgess and Bowring plan to determine an equally precise timeline for the Siberian Traps eruptions, and will compare it to the new extinction timeline to see where the two events overlap. The researchers will investigate additional areas in China to see if the duration of the extinction can be even more precisely determined.

ALFREDO ARIZMENDI's curator insight, February 11, 2015 4:07 AM

En un parpadeo geológico casi toda la vida sobre la faz de la Tierra puede verse barrida. Y mucho espacio adaptativo para los seres que permanecen queda abierto. La evolucion y el tiempo llenan estos espacios de nueva vida, hasta la siguiente extincion. Una rueda inexorable

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Germany: Former war bunker transformed into green energy power plant

Germany: Former war bunker transformed into green energy power plant | Amazing Science |

Energy and utilities company Hamburg Energie has joined forces with IBA Hamburg to transform a former Nazi anti-aircraft flak bunker into a green energy power plant. The Hamburg-based "Energy Bunker" has already begun producing energy for the local community, but once running at full capacity will provide up to 3,000 homes with heating, and another 1,000 homes with electricity.

Originally constructed in 1943 to serve as an anti-aircraft bunker, complete with gun turrets, the 42 m (137 ft) -high building also sheltered local people from Allied bombing raids during WWII. Though the British Army made an attempt to demolish the building on the war's close, blowing up its massively thick walls was deemed too dangerous to nearby buildings. The British ultimately settled on destroying much of the interior, and the bunker remained in this neglected state for over 60 years.

The Energy Bunker is outfitted with several sustainable technologies. The main feature is a 2 million liter (528,000 US gallon) water reservoir that acts as a large heat store and plugs into the existing Reiherstieg district heating network. The reservoir itself is heated by several methods: a biomass power plant and wood chip burning unit which feed into a large boiler, a solar thermal array installed on the roof of the bunker, and waste heat produced by a nearby industrial plant.

A large photovoltaic system is installed on the south-facing facade of the building to produce electricity, and the wood chip burning unit is also used to produce electricity. A peak-load boiler and large battery array ensure that the energy output is kept steady at all times.

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Clever technology decodes more information from single photons

Clever technology decodes more information from single photons | Amazing Science |

It's not quite Star Trek communications—yet. But long-distance communications in space may be easier now that researchers at the National Institute of Standards and Technology (NIST) and Jet Propulsion Laboratory (JPL) have designed a clever detector array that can extract more information than usual from single particles of light.

Described in a new paper, the NIST/JPL array-on-a-chip easily identifies the position of the exact detector in a multi-detector system that absorbs an incoming infrared light particle, or photon. That's the norm for digital photography cameras, of course, but a significant improvement in these astonishingly sensitive detectors that can register a single photon. The new device also records the signal timing, as these particular single-photon detectors have always done.

The technology could be useful in optical communications in space. Lasers can transmit only very low light levels across vast distances, so signals need to contain as much information as possible.

One solution is "pulse position modulation" in which a photon is transmitted at different times and positions to encode more than the usual one bit of information. If a light source transmitted photons slightly to the left/right and up/down, for instance, then the new NIST/JPL detector array circuit could decipher the two bits of information encoded in the spatial position of the photon. Additional bits of information could be encoded by using the arrival time of the photon.

The same NIST/JPL collaboration recently produced detector arrays for the first demonstration of two-way laser communications outside Earth's orbit using the timing version of pulse position modulation. The new NIST/JPL paper shows how to make an even larger array of detectors for future communications systems.

The new technology uses superconducting nanowire single-photon detectors. The current design can count tens of millions of photons per second but the researchers say it could be scaled up to a system capable of counting of nearly a billion photons per second with low dark (false) counts. The key innovation enabling the latest device was NIST's 2011 introduction of a new detector material, tungsten-silicide, which boosted efficiency, the ability to generate an electrical signal for each arriving photon. Detector efficiency now exceeds 90 percent. Other materials are less efficient and would be more difficult to incorporate into complex circuits.

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Fantastic Voyage: Nanomotors are inserted and controlled, for the first time, inside living cells

Fantastic Voyage: Nanomotors are inserted and controlled, for the first time, inside living cells | Amazing Science |

For the first time anywhere, a team of chemists and engineers at Penn State has placed tiny synthetic motors inside live human cells, propelled them with ultrasonic waves and steered them magnetically. It's not exactly "Fantastic Voyage," but it's close. The nanomotors, which are rocket-shaped metal particles, move around inside the cells, spinning and battering against the cell membrane.

"As these nanomotors move around and bump into structures inside the cells, the live cells show internal mechanical responses that no one has seen before," said Tom Mallouk, Evan Pugh Professor of Materials Chemistry and Physics. "This research is a vivid demonstration that it may be possible to use synthetic nanomotors to study cell biology in new ways. We might be able to use nanomotors to treat cancer and other diseases by mechanically manipulating cells from the inside. Nanomotors could perform intracellular surgery and deliver drugs noninvasively to living tissues."

Up until now, Mallouk said, nanomotors have been studied only "in vitro" in a laboratory apparatus, not in living human cells. Chemically powered nanomotors were first developed 10 years ago at Penn State by a team that included chemist Ayusman Sen and physicist Vincent Crespi, in addition to Mallouk.

"Our first-generation motors required toxic fuels and they would not move in biological fluid, so we couldn't study them in human cells," Mallouk said. "That limitation was a serious problem." When Mallouk and French physicist Mauricio Hoyos discovered that nanomotors could be powered by ultrasonic waves, the door was open to studying the motors in living systems.

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New live-cell printing technology improves on inkjet printing

New live-cell printing technology improves on inkjet printing | Amazing Science |

A new way to print living cells onto any surface and in almost any shape has been developed by researchers led by Houston Methodist Research Institute nanomedicine faculty member Lidong Qin. Unlike a similar inkjet printing process, almost all cells survive.

The new process, called Block-Cell-Printing (BloC-Printing), produces 2-D cell arrays in half an hour, prints the cells as close together as 5 microns (most animal cells are 10 to 30 microns wide), and allows the use of many different cell types.

“Cell printing is used in so many different ways now — for drug development and in studies of tissue regeneration, cell function, and cell-cell communication,” Qin said. “Such things can only be done when cells are alive and active. A survival rate of 50 to 80 percent is typical as cells exit the inkjet nozzles. “By comparison, we are seeing close to 100 percent of cells in BloC-Printing survive the printing process.”

BloC-Printing manipulates microfluidic physics to guide living cells into hook-like traps in the silicone mold. Cells flow down a column in the mold, past trapped cells to the next available slot, eventually creating a line of cells in a grid.

The position and spacing of the traps and the shape of the channel navigated by the cells is fully configurable during the mold’s creation. When the mold is lifted away, the living cells remain behind, adhering to the growth medium or other substrate, in prescribed formation.

The researchers also printed a grid of brain cells and gave the cells time to form synaptic and autaptic junctions. “The cell junctions we created may be useful for future neuron signal transduction and axon regeneration studies,” Qin said. “Such work could be helpful in understanding Alzheimer’s disease and other neurodegenerative diseases.”

While it is too early to predict the market cost of BloC-Printing, Qin said the materials of a single BloC mold cost about $1 (US). After the mold has been fabricated and delivered, a researcher only needs a syringe, a carefully prepared suspension of living cells, a Petri dish, and a steady hand, Qin said. Inkjet cell printers can cost between $10,000 and $200,000.

“BloC-Printing can be combined with molecular printing for many types of drug screening, RNA interference, and molecule-cell interaction studies,” he said. “We believe the technology has big potential.” While the fidelity of BloC-Printing is high, Qin said inkjet printing remains faster, and BloC-Printing cannot yet print multi-layer structures as inkjetting can.

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Special glasses help surgeons 'see' cancer​​​​​​​​ tissue during the operation

Special glasses help surgeons 'see' cancer​​​​​​​​ tissue during the operation | Amazing Science |
High-tech glasses may help surgeons visualize cancer cells, which glow blue when viewed through the eyewear. The wearable technology, so new it's yet unnamed, was used during surgery for the first time today at Alvin J. Siteman Cancer Center at Barnes-Jewish Hospital and Washington University School of Medicine.

The wearable technology, so new it's yet unnamed, was used during surgery for the first time today at Alvin J. Siteman Cancer Center at Barnes-Jewish Hospital and Washington University School of Medicine.

Cancer cells are notoriously difficult to see, even under high-powered magnification. The glasses are designed to make it easier for surgeons to distinguish cancer cells from healthy cells, helping to ensure that no stray tumor cells are left behind during surgery.

"We're in the early stages of this technology, and more development and testing will be done, but we're certainly encouraged by the potential benefits to patients," said breast surgeon Julie Margenthaler, MD, an associate professor of surgery at Washington University, who performed today's operation. "Imagine what it would mean if these glasses eliminated the need for follow-up surgery and the associated pain, inconvenience and anxiety."

Current standard of care requires surgeons to remove the tumor and some neighboring tissue that may or may not include cancer cells. The samples are sent to a pathology lab and viewed under a microscope. If cancer cells are found in neighboring tissue, a second surgery often is recommended to remove additional tissue that also is checked for the presence of cancer.

The glasses could reduce the need for additional surgical procedures and subsequent stress on patients, as well as time and expense.

Margenthaler said about 20 to 25 percent of breast cancer patients who have lumps removed require a second surgery because current technology doesn't adequately show the extent of the disease during the first operation

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Two independent science teams build heat cloaking device

Two independent science teams build heat cloaking device | Amazing Science |

Two teams have created two different types of thermal cloaking devices. In their papers, both published in Physical Review Letters, the teams describe how they went about creating their devices and offer suggestions as to what use they might be put.

Cloaking has a become a hot topic in science, and not just because of the popularity of Harry Potter. With the advent of metamaterials, scientists discovered they were able to create devices that bent microwaves—the first cloaking devices. Such devices were followed up by other devices that bent light and infrared radiation and sound—all cloaking devices which worked because of the way metamaterials were able to bend wave based media. In this new effort, the two research teams applied some of the same ideas to heat, which is of course, not a wave media—it moves via diffusion and therefore does not propagate. But, the researchers noted, that doesn't mean under certain circumstances it too can't be cloaked.

The idea behind cloaking heat is to create an environment where heat diffusion does not occur into an object placed into that environment—instead, like wave cloaking, the heat is caused to stray from its normal path and move around the object instead of into it.

The first team created a heat cloak by binding strips of metal and polystyrene together and then placing the result inside of a block made of thermal conducting material. The dimensions of all the materials were adjusted to meet those specified by a mathematical formula based on thickness and conductivity. The arrangement allowed for thermal cloaking of an aluminum cylinder placed inside.

The second team created their device by trapping a pocket of air inside a block made of stainless steel—the air pocket was lined with copper. An object placed inside the air pocket was heat cloaked.

Neither group has a specific application in mind for their heat cloaking device, but suggest heat cloaking might be useful for managing heat in electronic circuits. One such application might be inside of cell phones as way to prevent batteries from overheating. Both teams note that another result of their work is that they have proven that diffusion cloaking is possible which means it might be applied in other areas, such as with tomography or static currents.

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Mathematicians calculate that there are 177,147 ways to knot a tie, far more than previously thought

Mathematicians calculate that there are 177,147 ways to knot a tie, far more than previously thought | Amazing Science |

A small team of mathematicians, led by Mikael Vejdemo-Johansson of the of the KTH Royal Institute of Technology in Stockholm, has uploaded a paper to the preprint server arXiv describing a mathematical process they used to determine that the number of ways to tie a tie is 177,147—far more than previous research has suggested.

Most men don't consider more than one, two or maybe three ways to tie their tie, if they tie one at all—but the fact is, there are far more ways to do it than most would ever imagine and because of that mathematicians have at times set themselves the task of trying to discern if the number is finite, and if so, what that number might be.

Back in 1999, a pair of researches (Yong Mao and Thomas Fink) with the University of Cambridge came up with a mathematical language to describe all the actions that can be performed in tying a tie and used it to calculate that the total number of possible outcomes was a very reasonable 85. In this new effort the researchers say that number is far too small because it leaves out some good possibilities. They've extended the mathematical language and have used it to create a new upper limit—177,147.

Vejdemo-Johansson apparently came to believe that the number produced by Mao and Fink was too small after noting the unique tie knot in the movie "The Matrix Reloaded"—a knot that didn't appear in the researchers list, which meant something wasn't quite right. In reexamining the criteria that Mao and Fink used for inclusion, they noted the pair restricted the number of tucks that would occur at the end of the tie tying, to just one. The pair, it was noted, also assumed that any knot created would naturally be covered in part by a flat section of fabric. Also, they restricted the number of windings that could be made to just eight, believing any more than that would cause the tie to become too short.

Vejdemo-Johansson adjusted the parameters and added nomenclature for describing tie movements and after putting it all together, used their new math language to calculate the new total number of possible tie knots—though, it might not be the last word—some of their parameter assignments, such as setting the maximum winds at 11, for example, could perhaps be adjusted for longer ties, or those made of much thinner material.

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