Amazing Science
520.1K views | +112 today
Amazing Science
Amazing science facts - 3D_printing • aging • AI • anthropology • art • astronomy • bigdata • bioinformatics • biology • biotech • chemistry • computers • cosmology • education • environment • evolution • future • genetics • genomics • geosciences • green_energy • history • language • map • material_science • math • med • medicine • microscopy • nanotech • neuroscience • paleontology • photography • photonics • physics • postings • robotics • science • technology • video
Your new post is loading...
Scooped by Dr. Stefan Gruenwald!

'Habitable Zone' for Alien Planets, and Possibly Life, Redefined

'Habitable Zone' for Alien Planets, and Possibly Life, Redefined | Amazing Science |

The habitable zone defines the region where a planet might be able to retain liquid water on its surface. Any closer to the star and water would vaporize away; any farther, and it would freeze to ice. But water in its liquid state is what scientists are after, since that is thought to be a prerequisite for life.


The new definition of the habitable zone is based on updated atmospheric databases called HITRAN (high-resolution transmission molecular absorption) and HITEMP (high-temperature spectroscopic absorption parameters), which give the absorption parameters of water and carbon dioxide — two properties that strongly influence the atmospheres of exoplanets, determining whether those planets could host liquid water.


The scientists cautioned that the habitable zone definition still does not take into account feedback effects from clouds, which will also affect a planet's habitability.


The previous habitable zone definitions were derived about 20 years ago by Penn State researcher James Kasting, who was also part of the team behind the updates. "At the time when he wrote that paper no exoplanets were discovered," Kopparapu told "In 20 years, hundreds, maybe thousands have been discovered."

No comment yet.
Scooped by Dr. Stefan Gruenwald!

No more blind spots: Researchers design new rearview mirror

No more blind spots: Researchers design new rearview mirror | Amazing Science |

Today's motor vehicles in the United States use two different types of mirrors for the driver and passenger sides. The driver's side mirror is flat so that objects viewed in it are undistorted and not optically reduced in size, allowing the operator to accurately judge an approaching-from-behind vehicle's separation distance and speed. Unfortunately, the optics of a flat mirror also create a blind spot, an area of limited vision around a vehicle that often leads to collisions during merges, lane changes, or turns. The passenger side mirror, on the other hand, possesses a spherical convex shape. While the small radius of curvature widens the field of view, it also causes any object seen in it to look smaller in size and farther away than it actually is. Because of this issue, passenger side mirrors on cars and trucks in the United States must be engraved with the safety warning, "Objects in mirror are closer than they appear." In the European Union, both driver and passenger side mirrors are aspheric (One that bulges more to one side than the other, creating two zones on the same mirror).


The inner zone—the section nearest the door—has a nearly perfect spherical shape, while the outer zone— the section farthest from the door—becomes less and less curved toward the edges. The outer zone of this aspheric design also produces a similar distance and size distortion seen in spherical convex designs. In an attempt to remedy this problem, some automotive manufacturers have installed a separate, small wide-angle mirror in the upper corner of side mirrors. This is a slightly domed square that provides a wide-angle view similar to a camera's fisheye lens. However, drivers often find this system to be a distracting as well as expensive addition.


A simpler design for a mirror that would be free of blind spots, have a wide field of view, and produce images that are accurately scaled to the true size of an approaching object—and work for both sides of a vehicle—has been proposed by researchers Hocheol Lee and Dohyun Kim at Hanbat National University in Korea and Sung Yi at Portland State University in Oregon. Their solution was to turn to a progressive additive optics technology commonly used in "no-line multifocal" eyeglasses that simultaneously corrects myopia (nearsightedness) and presbyopia (reduced focusing ability).

No comment yet.
Scooped by Dr. Stefan Gruenwald!

Einstein’s Brain

Einstein’s Brain | Amazing Science |

Scientists have been studying Albert Einstein's dead brain for clues as to his genius. Einstein’s brain is of unexceptional size and its combination of a relatively wide and forward-projecting right frontal lobe with a relatively wide and posteriorly protruding left occipital lobe is the most prevalent pattern seen in right-handed adult males. Scientests have identified the sulci that delimit expansions of cortex (gyri or convolutions) on the external surfaces of all of the lobes of the brain and on the medial surfaces of both hemispheres. The morphology in some parts of Einstein’s cerebral cortex is highly unusual compared with control human brains for which sulcal patterns have been thoroughly described. To the extent possible, the blocks of brain from particularly interesting areas are identified on the ‘roadmap’ that was prepared when Einstein’s brain was sectioned, as a guide for researchers who may wish to explore the histological correlates of Einstein’s gross cortical morphology.

Contrary to earlier reports, newly available photographs reveal that Einstein’s brain is not spherical in shape. The surface area of Einstein’s inferior parietal lobule is larger on the left than the right side, whereas that of his superior parietal lobule appears markedly larger in the right hemisphere. The photographs also suggest that the primary somatosensory and motor cortices representing the face and tongue are differentially expanded in the left hemisphere, that the posterior ascending limb of the Sylvian fissure is separate from (rather than confluent with) the postcentral inferior sulcus, and that parietal opercula are present. Nevertheless, these findings are concordant with the earlier suggestion that unusual morphology in Einstein’s parietal lobes may have provided neurological substrates for his visuospatial and mathematical abilities.

These results also suggest that Einstein had relatively expanded prefrontal cortices, which may have provided underpinnings for some of his extraordinary cognitive abilities, including his product- ive use of thought experiments. From an evolutionary perspective, the specific parts of Einstein’s prefrontal cortex that appear to be differentially expanded are of interest because recent findings indicate that these same areas increased differentially in size and became neurologically reorganized at microanatomical levels during hominin evolution in association with the emergence of higher cog- nitive abilities. It would be interesting therefore to investigate the histological correlates of these (as well as parietal) regions of Einstein’s brain from the newly available slides. Future research on comparative primate neuroanatomy, paleoneurology and functional neuroanatomy will hopefully provide insight about some of the unusually convoluted parts of Einstein’s brain.

No comment yet.
Scooped by Dr. Stefan Gruenwald!

Scientists Characterize Spider Silk Using Non–Invasive Laser Light Scattering Technique

Scientists Characterize Spider Silk Using Non–Invasive Laser Light Scattering Technique | Amazing Science |
Scientists at ASU are celebrating their recent success on the path to understanding what makes the fiber that spiders spin – weight for weight - at least five times as strong as piano wire. They have found a way to obtain a wide variety of elastic properties of the silk of several intact spiders’ webs using a sophisticated but non–invasive laser light scattering technique.


“Spider silk has a unique combination of mechanical strength and elasticity that make it one of the toughest materials we know,” said Professor Jeffery Yarger of ASU’s Department of Chemistry and Biochemistry, and lead researcher of the study. “This work represents the most complete understanding we have of the underlying mechanical properties of spider silks.” 

Spider silk is an exceptional biological polymer, related to collagen (the stuff of skin and bones) but much more complex in its structure. The ASU team of chemists is studying its molecular structure in an effort to produce materials ranging from bulletproof vests to artificial tendons.


No comment yet.
Scooped by Dr. Stefan Gruenwald!

Ancient pigment extracted from 340 million-year-old crinoid fossils

Ancient pigment extracted from 340 million-year-old crinoid fossils | Amazing Science |

Many fossils are tinted with color, but few have had their pigments chemically analyzed. Now, researchers are reporting the oldest pigment molecules extracted from fossils of a known organism—namely, approximately 340 million-year-old fossils of marine animals called crinoids, which are related to sea cucumbers, starfish, and urchins.


The techniques used to measure the pigments could be easily applied to other tinted fossils, says Christina E. O’Malley, who did the analysis with paleontologist William I. Ausich and chemist Yu-Ping Chin, all of Ohio State University. In addition to reconstructing the color palette of ancient organisms, O’Malley hopes that organic molecules preserved in ancient fossils could help unravel phylogenetic relationships among fossilized and contemporary organisms.


Crinoid fossils can vary in color from white to brown and reddish purple, O’Malley says. After taking about a gram of sample from fossils of three crinoid species, Barycrinus rhombiferus, Cyathrocrinites iowensis, and Elegantocrinus hemiohaericus, the team identified a complex mixture of pigments that corresponded to aromatic or polyaromatic quinones.


This is not the first time researchers have identified pigment residues on fossils, although it is an emerging field. For example, in 2011, paleochemists identified the feather color of ancient winged dinosaurs from 120 million-year-old fossils, some 220 million years younger than the crinoid fossils.

No comment yet.
Scooped by Dr. Stefan Gruenwald!

Saliva Test for Red Hair Gene Developed

Saliva Test for Red Hair Gene Developed | Amazing Science |

A British ancestry company, BritainsDNA, is now offering parents the chance to see if their children might inherit the so-called "ginger gene". The test will scan each parent's DNA for signs of the so-called MC1R gene that causes redheadedness.


"Through a simple saliva test to determine deep ancestry, we can … identify whether an individual is a carrier of any of the three common redhead variants in the gene MC1R," said Dr. Jim Wilson, chief scientist at BritainsDNA, as quoted in the Huffington Post.


The gene for red hair is recessive, so a person needs two copies of that gene for it to show up or be expressed. That means even if both parents carry the gene, just one in four of their children are likely to turn out to be a redhead. As a result, families that have no redheads for decades can suddenly discover a carrottop in their midst.


"Families can carry a variant for generations, and when one carrier has children with another carrier, a redheaded baby can appear seemingly out of nowhere." Wilson said, as quoted in the Daily Mail.


Though there's no scientific evidence that redheads deserve their reputation for having fiery temperaments, some recent reports suggest having red hair is associated with a number of health issues. A study from the journal Nature found that the pigment pheomelanin, which is responsible for red hair, may also make redheads even more susceptible to melanoma than fair-skinned blondes, according to the Los Angeles Times.


And a widely reported study from the Journal of the American Dentistry Association found that redheads are more sensitive to pain and require extra anesthesia during surgery, according to ABC News.


But there may be some advantages to having red hair, too, reports. The pale skin that redheads usually have is more efficient at soaking up sunlight — and sunlight is required for the body to manufacture vitamin D, an essential nutrient.


Worldwide, red hair is quite rare, and just over 0.5 percent, or one in 200 people, are redheads — this amounts to almost 40 million people, the Daily Mail reports.


In Ireland, an estimated 10 percent of the population has red hair, though about 40 percent of the Irish carry the recessive gene. In Scotland and England, 13 percent and 6 percent, respectively, are redheaded, according to the Daily Mail.


The DNA test will be offered by BritainsDNA at a genealogy and ancestry exhibition named Who Do You Think You Are, associated with the popular NBC television show and scheduled to be held in London next month.


No comment yet.
Scooped by Dr. Stefan Gruenwald!

'Quantum physics of smell' gains experimental new ground with human subjects

'Quantum physics of smell' gains experimental new ground with human subjects | Amazing Science |
A controversial theory of smell involving quantum physics receives a boost as scientists test the idea using human subjects.


The human sense of smell uses the input from several hundred receptors to discriminate between tens of thousands of odorants. Although human olfactory receptors are members of the G-protein coupled receptor superfamily, the exact mechanism by which an odorant activates a receptor is still unclear. Specifically, we do not know whether olfactory receptors detect the shape of odorant molecules by a classical lock-and-key mechanism, their vibrations by a quantum mechanism, or a combination of both.


In principle, odorant isotopomers provide a possible test of shape vs. vibration mechanisms: replacing, for example, hydrogen with deuterium in an odorant leaves the ground-state conformation of the molecule unaltered while doubling atomic mass and so altering the frequency of all its vibrational modes to a greater or lesser extent. To first order, deuteration should therefore have little or no effect on the smell character of an odorant recognized by shape, whereas deuterated isotopomers should smell different if a vibrational mechanism is involved.


The experimental evidence on this question to date is contradictory.  Drosophila appears able to recognize the presence of deuterium in odorant isotopomers by a vibrational mechanism. Partial deuteration of insect pheromones reduces electroantennogram response amplitudes. Fish have been reported to be able to distinguish isotopomers of glycine by smell. However, human trials using commercially available deuterated odorants [benzaldehyde and acetophenone] have yielded conflicting results, both positive and negative. Using GC-pure samples and a different experimental technique, Keller and Vosshall found that humans, both naive and trained subjects, are unable to discriminate between acetophenone isotopomers. However, since deuteration exerts the largest effect on the parts of the vibrational spectrum involving C-H motions, it seemed interesting to ask whether the effect of deuterium–if any–on smell character might be detectable in odorants containing more carbons, and therefore more CH groups.


Musks are among the largest odorants and typically contain 15–18 carbons and 28 or more hydrogens, as compared to 8 carbons and 8 hydrogens for acetophenone. This new research now reports that deuterated musks of diverse structures smell strikingly different from the parent compounds and similar to each other, even to naive subjects. The difference in smell character caused by deuteration persists when the most stringent criterion of purity, preparative gas-chromatography, is used.

No comment yet.
Rescooped by Dr. Stefan Gruenwald from Social Foraging!

The science behind 'beatboxing'

The science behind 'beatboxing' | Amazing Science |

Using the mouth, lips, tongue and voice to generate sounds that one might never expect to come from the human body is the specialty of the artists known as beatboxers. Now scientists have used scanners to peer into a beatboxer as he performed his craft to reveal the secrets of this mysterious art.


The human voice has long been used to generate percussion effects in many cultures, including North American scat singing, Celtic lilting and diddling, and Chinese kouji performances. In southern Indian classical music, konnakol is the percussive speech of the solkattu rhythmic form.  In contemporary pop music, the relatively young vocal art form of beatboxing is an element of hip-hop culture.


Until now, the phonetics of these percussion effects were not examined in detail. For instance, it was unknown to what extent beatboxers produced sounds already used within human language.

Via Ashish Umre
Olaf Husby's curator insight, March 11, 6:50 PM

Idrett på høyt nivå.

Scooped by Dr. Stefan Gruenwald!

Dolphins form life raft to help injured and dying friend

Dolphins form life raft to help injured and dying friend | Amazing Science |


A group of dolphins was caught on camera as they worked together to keep a struggling dolphin above water by forming an impromptu raft.


For the first time, dolphins have been spotted teaming up to try to rescue an injured group member. The act does not necessarily mean dolphins are selfless or can empathise with the pain of their kin, however.


Kyum Park of the Cetacean Research Institute in Ulsan, South Korea, and colleagues were surveying cetaceans in the Sea of Japan in June 2008. They spent a day following a group of about 400 long-beaked common dolphins (Delphinus capensis).


In the late morning they noticed that about 12 dolphins were swimming very close together. One female was in difficulties: it was wriggling and tipping from side to side, sometimes turning upside-down. Its pectoral flippers seemed to be paralysed.


The other dolphins crowded around it, often diving beneath it and supporting it from below. After about 30 minutes, the dolphins formed into an impromptu raft: they swam side by side with the injured female on their backs. By keeping the injured female above water, they may have helped it to breathe, avoiding drowning.


After another few minutes some of the helper dolphins left. The injured dolphin soon dropped into a vertical position. The remaining helpers appeared to try and prop it up, possibly to keep its head above the surface, but it soon stopped breathing, say the researchers. Five dolphins stayed with it and continued touching its body, until it sank out of sight.


"It does look like quite a sophisticated way of keeping the companion up in the water," says Karen McComb at the University of Sussex in Brighton, UK. Such helping behaviours are only seen in intelligent, long-lived social animals. In most species, injured animals are quickly left behind.

No comment yet.
Scooped by Dr. Stefan Gruenwald!

Scientists Discover Children’s Cells Living in Mothers’ Brains

Scientists Discover Children’s Cells Living in Mothers’ Brains | Amazing Science |

The connection between mother and child is ever deeper than thought.


What it is that fetal microchimeric cells do in the mother’s body is unclear, although there are some intriguing possibilities. For example, fetal microchimeric cells are similar to stem cells in that they are able to become a variety of different tissues and may aid in tissue repair. One research group investigating this possibility followed the activity of fetal microchimeric cells in a mother rat after the maternal heart wasinjured: they discovered that the fetal cells migrated to the maternal heart and differentiated into heart cells helping to repair the damage. In animal studies, microchimeric cells were found in maternal brains where they became nerve cells, suggesting they might be functionally integrated in the brain. It is possible that the same may true of such cells in the human brain.


These microchimeric cells may also influence the immune system. A fetal microchimeric cell from a pregnancy is recognized by the mother’s immune system partly as belonging to the mother, since the fetus is genetically half identical to the mother, but partly foreign, due to the father’s genetic contribution. This may “prime” the immune system to be alert for cells that are similar to the self, but with some genetic differences. Cancer cells which arise due to genetic mutations are just such cells, and there are studies which suggest that microchimeric cells may stimulate the immune system to stem the growth of tumors. Many more microchimeric cells are found in the blood of healthy women compared to those withbreast cancer, for example, suggesting that microchimeric cells can somehow prevent tumor formation. In other circumstances, the immune system turns against the self, causing significant damage. Microchimerism is more common in patients suffering from Multiple Sclerosis than in their healthy siblings, suggesting chimeric cells may have a detrimental role in this disease, perhaps by setting off an autoimmune attack.

No comment yet.
Scooped by Dr. Stefan Gruenwald!

Dominant-negative p53 mutation hinders cancer treatment response

Dominant-negative p53 mutation hinders cancer treatment response | Amazing Science |

The p53 gene is the major tumor suppressor in humans and is generally found mutated in over 50% of all human cancers.


The dominant-negative (DN) effect of the mutant p53 gene in cancers was found to affect the outcome of cancer treatment modalities. DN effect is a phenomenon whereby one copy of mutant p53 that exists in cancer cells inhibits the tumor suppressor activity of the other wild-type p53 copy when they co-exist. The result is that a patient may either have poor response or earlier relapse of tumours after their treatment.


The research findings is significant in that it offers hope to improve cancer treatment outcomes by selectively inhibiting mutant p53's DN effect through several methods by generating selective and specific inhibitory molecules specific for some of the common hot-spot p53 point mutations. There are currently no drugs or compounds that can alleviate DN effects of mutant p53.


In order to understand the specific roles of mutant p53 DN properties in regulating acute treatment response and long-term tumourgenesis, a team of five researchers led by NCCS Prof Kanaga Sabapathy, the Principal Investigator in the Laboratory of Carcinogenesis and Head of the Division of Cellular & Molecular Research from NCCS, carried out experiments by generating genetically engineered knock-in mouse strains expressing varying levels of mutant p53. The results showed that DN effect is observed after acute p53 activation by a variety of chemotherapeutic drugs and irradiation, thereby affecting anti-cancer treatment.


It was found that mutant p53 have DN effects in a cell-type and dose-dependent manner, especially during acute p53 activation where p53 levels are elevated. Based on the above observations, efforts to generate specific inhibitors for the common hot spot p53 point mutations are underway. The inhibition of mutant p53 expression in cells carrying a wild-type and mutant p53 alleles can improve response to chemotherapeutic drugs.

No comment yet.
Scooped by Dr. Stefan Gruenwald!

German researcher achieves breakthrough in building efficient single-photon detector

German researcher achieves breakthrough in building efficient single-photon detector | Amazing Science |

Ultrafast, efficient, and reliable single-photon detectors are among the most sought-after components in photonics and quantum communication, which have not yet reached maturity for practical application. Physicist Dr. Wolfram Pernice of the Karlsruhe Institute of Technology (KIT), in cooperation with colleagues at Yale University, Boston University, and Moscow State Pedagogical University, achieved the decisive breakthrough by integrating single-photon detectors with nanophotonic chips. The detector combines near-unity detection efficiency with high timing resolution and has a very low error rate.


Without reliable detection of single photons, it is impossible to make real use of the latest advances in optical data transmission or quantum computation; it is like having no analog-digital converter in a conventional computer to determine whether the applied voltage stands for 0 or 1. Although a number of different single-photon detector models have been developed over the past few years, thus far, none have provided satisfactory performance.


Several new ideas and advanced developments went into the prototype developed within the "Integrated Quantum Photonics" project at the DFG Center of Functional Nanostructures (CFN). The new single-photon detector, tested in the telecommunications wavelength range, achieves a previously unattained detection efficiency of 91%.


The detector was realized by fabricating superconducting nanowires directly on top of a nanophotonic waveguide. This geometry can be compared to a tube that conducts light, around which a wire in a superconducting state is wound and, as such, has no electric resistivity. The nanometer-sized wire made of niobium nitride absorbs photons that propagate along the waveguide. When a photon is absorbed, superconductivity is lost, which is detected as an electric signal. The longer the tube, the higher is the detection probability. The lengths involved are in the micrometer range.


A special feature of the detector is its direct installation on the chip, which allows for it to be replicated at random. The single-photon detectors built thus far were stand-alone units, which were connected to chips with optical fibers. Arrangements of that type suffer from photons being lost in the fiber connection or being absorbed in other ways. These loss channels do not exist in the detector that is now fully embedded in a silicon photonic circuit. In addition to high detection efficiency, this gives rise to a remarkably low dark count rate. Dark counts arise when a photon is detected erroneously: for instance, because of a spontaneous emission, an alpha particle, or a spurious field. The new design also provides ultrashort timing jitter of 18 picoseconds, which is 18 times 10^-12 seconds.


The novel solution also makes it possible to integrate several hundreds of these detectors on a single chip. This is a basic precondition for future use in optical quantum computers. The detector demonstrated in this study was designed to work at wavelengths in the Telekom bandwidth. The same detector architecture can also be used for wavelengths in the range of visible light. This would allow the principle to be employed in analyses of all structures that emit little light, i.e., photons, such as single molecules or bacteria.

No comment yet.
Scooped by Dr. Stefan Gruenwald!

Long non-coding RNA molecule "Braveheart" necessary to regulate differentiation of embryonic stem cells into cardiac cells

Long non-coding RNA molecule "Braveheart" necessary to regulate differentiation of embryonic stem cells into cardiac cells | Amazing Science |
When the human genome was sequenced, biologists were surprised to find that very little of the genome—less than 3 percent—corresponds to protein-coding genes. What, they wondered, was all the rest of that DNA doing?


It turns out that much of it codes for genetic snippets known as long non-coding RNAs, or lncRNAs. In recent years, scientists have found that these molecules often help to regulate which genes get turned on or off inside a cell. However, little is known about the specific roles of the thousands of lncRNAs discovered so far. In a new study, MIT biologists have identified a critical role for a lncRNA they dubbed "Braveheart." This lncRNA appears to stimulate stem cells to transform into heart cells during mouse embryonic stem cell (ESC) differentiation; the researchers suspect that lncRNAs may control this process in humans as well. If so, learning more about lncRNAs could offer a new approach to developing regenerative drugs for patients whose hearts have been damaged by cardiovascular disease or aging. "It opens a new door to what we could do, and how we could use lncRNAs to induce specific cell types, that's been completely unexplored," says Carla Klattenhoff, a postdoc in MIT's Department of Biology and one of the lead authors of a paper describing the findings in the Jan. 24 online edition of Cell. MIT postdoc Johanna Scheuermann is also a lead author of the paper. Senior author is Laurie Boyer, the Irwin and Helen Sizer Career Development Associate Professor of Biology at MIT. The researchers zeroed in on the Braveheart lncRNA because they had noticed that it is abundant both in ESCs and in differentiating heart cells. In the new study, they found that without normal levels of the Braveheart lncRNA, mouse ESCs did not develop any of the three major types of heart cells that comprise the cardiovascular system—cardiomyocytes (which make up cardiac muscle), smooth muscle cells and endothelial cells.

No comment yet.
Scooped by Dr. Stefan Gruenwald!

Assembly of a three-dimensional multitype tissue structures using magnetic levitation

Assembly of a three-dimensional multitype tissue structures using magnetic levitation | Amazing Science |

A longstanding goal in biomedical research has been to create organotypic co-cultures that faithfully represent native tissue environments. There is presently great interest in representative culture models of the lung, which is a particularly challenging tissue to recreate in vitro. This study used magnetic levitation in conjunction with magnetic nanoparticles as a means of creating an organized 3D co-culture of the bronchiole that sequentially layers cells in a manner similar to native tissue architecture. The 3D co-culture model was assembled from four human cell types in the bronchiole: endothelial cells, smooth muscle cells, fibroblasts, and epithelial cells. This study represents the first effort to combine these particular cell types into an organized bronchiole co-culture. These cell layers were first cultured in 3D by magnetic levitation and then manipulated into contact with a custom-made magnetic pen, and again cultured for 48 h. Hematoxylin & eosin staining of the resulting co-culture showed four distinct layers within the 3D co-culture.


Immunohistochemistry confirmed the phenotype of each of the four cell types, and showed organized extracellular matrix formation, particularly with collagen type I. Positive stains for CD31, von Willebrand factor, smooth muscle α-actin, vimentin, and fibronectin demonstrate the maintenance of phenotype for endothelial cells, smooth muscle cells, and fibroblasts. Positive stains for mucin-5AC, cytokeratin, and E-cadherin after 7 days with and without 1% FBS showed that epithelial cells maintained phenotype and function. This study validates magnetic levitation as a method for the rapid creation of organized 3D co-cultures that maintain phenotype and induce extracellular matrix formation.


See also Nano3D:


No comment yet.
Scooped by Dr. Stefan Gruenwald!

Norwegians trap sunlight with microbeads, produce solar cells that are 20 times thinner, cheaper

Norwegians trap sunlight with microbeads, produce solar cells that are 20 times thinner, cheaper | Amazing Science |

Researchers from the University of Oslo have used a bunch of “wonderful tricks” to produce silicon solar cells that are twenty times thinner than commercial solar cells. This breakthrough means that solar cells can be produced using 95% less silicon, reducing production costs considerably — both increasing profits (which are almost nonexistent at the moment), and reducing the cost of solar power installations.


Standard, commercial photovoltaic solar cells are fashioned out of 200-micrometer-thick (0.2mm) wafers of silicon, which are sliced from a large block of silicon. This equates to around five grams of silicon per watt of solar power, and also a lot of wastage — roughly half of the silicon block is turned into sawdust by the slicing process. With solar cells approaching 50 cents per watt (down from a few dollars per watt a few years ago), something needs to change.


Reducing the thickness of solar cells obviously makes a lot of sense from a commercial point of view, but it introduces another issue: As the wafer gets thinner, more light passes straight through the silicon, dramatically reducing the amount of electricity produced by the photovoltaic effect. This is due to wavelengths: Blue light, which has a short wavelength (450nm), can be captured by a very thin wafer of silicon — but red light, with a longer wavelength (750nm), can only be captured by thicker slabs of silicon. This is part of the reason that current solar cells use silicon wafers that are around 200 micrometers — and also why they’re mirrored, which doubles the effective thickness, allowing them to capture more of the visible spectrum.

No comment yet.
Scooped by Dr. Stefan Gruenwald!

Bioinspired fibers change color when stretched

Bioinspired fibers change color when stretched | Amazing Science |

Color-tunable photonic fibers mimic the fruit of the “bastard hogberry” plant.


Since the evolution of the first eye on Earth more than 500 million years ago, the success of many organisms has relied upon the way they interact with light and color, making them useful models for the creation of new materials. For seeds and fruit in particular, bright color is thought to have evolved to attract the agents of seed dispersal, especially birds.


The fruit of the South American tropical plant, Margaritaria nobilis, commonly called “bastard hogberry,” is an intriguing example of this adaptation. The ultra-bright blue fruit, which is low in nutritious content, mimics a more fleshy and nutritious competitor. Deceived birds eat the fruit and ultimately release its seeds over a wide geographic area.


A team of materials scientists at Harvard University and the University of Exeter, UK, have invented a new fiber that changes color when stretched. Inspired by nature, the researchers identified and replicated the unique structural elements that create the bright iridescent blue color of a tropical plant’s fruit.


The multilayered fiber, described today in the journal Advanced Materials, could lend itself to the creation of smart fabrics that visibly react to heat or pressure.


“Our new fiber is based on a structure we found in nature, and through clever engineering we’ve taken its capabilities a step further,” says lead author Mathias Kolle, a postdoctoral fellow at the Harvard School of Engineering and Applied Sciences (SEAS). “The plant, of course, cannot change color. By combining its structure with an elastic material, however, we’ve created an artificial version that passes through a full rainbow of colors as it’s stretched.”


The photonic fibers are made by wrapping multiple layers of polymer around a glass core, which is later etched away. The thickness of the layers determines the apparent color of the fiber, which can range across the entire visible spectrum of light (see image).

Team's curator insight, October 23, 2014 2:44 AM

Julien : Possibilité de modificaition de la couleur de fibres en fonction de la déformation ou de la température

Team's curator insight, November 1, 2014 2:31 PM

Philippe Potentiellement nterssant

Scooped by Dr. Stefan Gruenwald!

Microbes Survive and Maybe Even Thrive High in the Atmosphere

Microbes Survive and Maybe Even Thrive High in the Atmosphere | Amazing Science |

Each year, hundreds of millions of metric tons of dust, water, and human-made pollutants make their way into the atmosphere, often traveling between continents on jet streams. Now a new study confirms that some microbes make the trip with them, seeding the skies with billions of bacteria and other organisms—and potentially affecting the weather. What's more, some of these high-flying organisms may actually be able to feed while traveling through the clouds, forming an active ecosystem high above the surface of the Earth.


The discovery came about when a team of scientists based at the Georgia Institute of Technology in Atlanta hitched a ride on nine NASA airplane flights aimed at studying hurricanes. Previous studies carried out at the tops of mountains hinted that researchers were likely to find microorganisms at high altitudes, but no one had ever attempted to catalog the microscopic life floating above the oceans—let alone during raging tropical storms. After all, it isn't easy to take air samples while your plane is flying through a hurricane.


Despite the technical challenges, the researchers managed to collect thousands upon thousands of airborne microorganisms floating in the troposphere about 10 kilometers over the Caribbean, as well as the continental United States and the coast of California. Studying their genes back on Earth, the scientists counted an average of 5100 bacterial cells per cubic meter of air. Although the researchers also captured various types of fungal cells, the bacteria were over two orders of magnitude more abundant in their samples. Well over 60% of all the microbes collected were still alive.


The researchers cataloged a total of 314 different families of bacteria in their samples. Because the type of genetic analysis they used didn't allow them to identify precise species, it's not clear if any of the bugs they found are pathogens. Still, the scientists offer the somewhat reassuring news that bacteria associated with human and animal feces only showed up in the air samples taken after Hurricanes Karl and Earl. In fact, these storms seemed to kick up a wide variety of microbes, especially from populated areas, that don't normally make it to the troposphere.


Although many of the organisms borne aloft are likely occasional visitors to the upper troposphere, 17 types of bacteria turned up in every sample. Researchers like environmental microbiologist and co-author Kostas Konstantinidis suspect that these microbes may have evolved to survive for weeks in the sky, perhaps as a way to travel from place to place and spread their genes across the globe. "Not everybody makes it up there," he says. "It's only a few that have something unique about their cells" that allows them survive the trip.

No comment yet.
Scooped by Dr. Stefan Gruenwald!

Lingering kiss: DNA persists in the mouth after kiss for over 1 hour

Lingering kiss: DNA persists in the mouth after kiss for over 1 hour | Amazing Science |

A kiss is not just a kiss – it's bacteria, mucus and DNA. When you kiss your partner passionately, not only do you exchange bacteria and mucus, you also impart some of your genetic code. No matter how fleeting the encounter, the DNA will hang around in their mouth for at least an hour. This means that women's saliva could contain evidence of unwanted attention in cases of assault, or even telltale signs of infidelity.


Natália Kamodyová and her colleagues at Comenius University in Bratislava, Slovakia, recruited 12 couples who agreed to kiss each other passionately for at least 2 minutes. Afterwards, saliva samples were collected from the women at 5, 10, 30 and 60-minute intervals. Because Kamodyová's method relies on detection of the Y chromosome, it can only be used to identify a man's DNA in a woman's saliva.


The results show that the man's DNA was still present and could be detected through amplification after at least an hour, and possibly longer. "We've shown it's possible to get a full profile, which could be useful in crime investigation to pinpoint the possible perpetrator among suspects or exclude those innocent," says Kamodyová. Her team is investigating whether the DNA survives longer than an hour and whether it's obtainable from the mouths of women who have died.

No comment yet.
Scooped by Dr. Stefan Gruenwald!

Polymer film that gradually releases DNA provides a safer way to vaccinate

Polymer film that gradually releases DNA provides a safer way to vaccinate | Amazing Science |
Polymer film that gradually releases DNA coding for viral proteins could offer a better alternative to traditional vaccines.


Vaccines usually consist of inactivated viruses that prompt the immune system to remember the invader and launch a strong defense if it later encounters the real thing. However, this approach can be too risky with certain viruses, including HIV.

In recent years, many scientists have been exploring DNA as a potential alternative vaccine. About 20 years ago, DNA coding for viral proteins was found to induce strong immune responses in rodents, but so far, tests in humans have failed to duplicate that success.


MIT researchers describe a new type of vaccine-delivery film that holds promise for improving the effectiveness of DNA vaccines. If such vaccines could be successfully delivered to humans, they could overcome not only the safety risks of using viruses to vaccinate against diseases such as HIV, but they would also be more stable, making it possible to ship and store them at room temperature.

This type of vaccine delivery would also eliminate the need to inject vaccines by syringe, says Darrell Irvine, an MIT professor of biological engineering and materials science and engineering. “You just apply the patch for a few minutes, take it off and it leaves behind these thin polymer films embedded in the skin,” he says.


The researchers can control how much DNA gets delivered by tuning the number of polymer layers. They can also control the rate of delivery by altering how hydrophobic (water-fearing) the film is. DNA injected on its own is usually broken down very quickly, before the immune system can generate a memory response. When the DNA is released over time, the immune system has more time to interact with it, boosting the vaccine’s effectiveness.

The polymer film also includes an adjuvant — a molecule that helps to boost the immune response. In this case, the adjuvant consists of strands of RNA that resemble viral RNA, which provokes inflammation and recruits immune cells to the area.

The ability to provoke inflammation is one of the key advantages of the new delivery system, says Michele Kutzler, an assistant professor at Drexel University College of Medicine. Other benefits include targeting the wealth of immune cells in the skin, the use of a biodegradable delivery material, and the possibility of pain-free vaccine delivery, she says.

No comment yet.
Scooped by Dr. Stefan Gruenwald!

Scientists Take First Glimpse at Interior of an Antarctic Subglacial Lake

Scientists Take First Glimpse at Interior of an Antarctic Subglacial Lake | Amazing Science |

Scientists have peered for the first time into the interior of a lake hidden beneath the Antarctic ice sheet. Subglacial Lake Whillans, located less than 400 miles from the South Pole, had sat isolated under the ice for hundreds of thousands of years—perhaps up to a million years. But over the last week a team of ice drillers has used a jet of hot water to melt a narrow hole into the lake through 2,600 feet of ice.


Final confirmation that the lake had been reached unfolded inside a steel shipping container parked on the ice sheet on four massive skis. Seventeen people crowded into this mobile control room as a video camera was lowered into the borehole. All eyes were riveted to a computer monitor. A scene reminiscent of cosmic wormhole travel unfolded on it: the camera steered into the black void at the center of the screen; the smooth, round, undulating walls of ice-hole scrolled by on the edges.


Billowing clouds obscured the camera’s view in the lower reaches of the hole. Then, as the swirling silt settled, a fuzzy picture emerged: the camera lay on its side, its lens looking across a muddy brown bottom strewn with small rocks. Wisps of mud drifted above. The image, knitted in rows of grainy pixels, echoed the first pictures of the Martian surface, radioed back by the Viking lander almost 40 years ago.


The door of the control room opened and in stepped a woman covered head to ankle in a sterile white Tyvek suit—Jill Mikucki, a microbiologist from the University of Tennessee in Knoxville who had helped lower the camera into the lake. Mikucki pointed her own little Canon at the image on the computer monitor and tried to snap a photo—“Oh,” she murmured, disappointed: the cold had killed her batteries. She paused. “It’s beautiful,” she said, forced to appreciate it in the moment—“really beautiful”—then she hurried out to help retrieve the camera.

No comment yet.
Scooped by Dr. Stefan Gruenwald!

The First Oxygen Users 2.9 Billion years ago

The First Oxygen Users 2.9 Billion years ago | Amazing Science |

Researchers believe that ancient archaea, similar in shape to this Halobacteria, used aerobic respiration 2.9 billion years ago to produce an active form of vitamin B6


Billions of years ago, a tiny, single-celled organism started using oxygen. It is not exactly known when this happened, or why, but a team of scientists has come closer than ever before to finding that out. They have identified the earliest known example of an aerobic metabolism, the process of using oxygen as fuel. The discovery may even provide clues as to where the oxygen came from in the first place.


To travel so far back in time, evolutionary bioinformaticist Gustavo Caetano-Anollés of the University of Illinois, Urbana-Champaign, along with colleagues in China and South Korea, did a bit of molecular sleuthing. They scoured published genomes from all groups of organisms-although they didn't include viruses in this study-focusing on pieces of proteins known as domains. These pieces have their own distinguishing shapes that provide clues to the protein's function and can be categorized based on various characteristics. Just like a Victorian house has certain features that set it apart from a Tudor mansion, researchers can tell the difference between different domains based on their shape.


The team produced a kind of molecular clock by establishing an evolutionary sequence for single-domain proteins. Caetano-Anollés and his colleagues could then tie that sequence to the geologic timeline. By correlating the appearance of domains integral to events such as the rise of eukaryotes, organisms with membrane-bound cellular structures, they could determine an approximate date for the origin of particular domains. "Molecular clocks aren't perfect," Caetano-Anollés acknowledges. "And sometimes they misbehave. But the [domains] that we sampled that were linked to clear-cut events had good agreement."


The researchers found that the most ancient aerobic process was the production of pyridoxal, or the active form of vitamin B6, they report today in Structure. This reaction appeared about 2.9 billion years ago, along with an oxygen-producing enzyme called manganese catalase. This enzyme detoxifies hydrogen peroxide by breaking it down into water and oxygen. Caetano-Anollés hypothesizes that early organisms got the oxygen they needed to produce vitamin B6 from this breakup of hydrogen peroxide. The authors argue that these ancient organisms would have encountered massive amounts of hydrogen peroxide in their environment due to the bombardment of glacial ice by ultraviolet radiation, which can generate the compound.

No comment yet.
Scooped by Dr. Stefan Gruenwald!

Cities affect weather thousands of kilometres away

Cities affect weather thousands of kilometres away | Amazing Science |

Heat from large cities alters local streams of high-altitude winds, potentially affecting weather in locations thousands of kilometres (miles) away. The findings could explain a long-running puzzle in climate change -- why some regions in the northern hemisphere are strangely experiencing warmer winters than computer models have forecast.


Cities generate vast amounts of waste heat, from cars, buildings and power stations, which burn oil, gas and coal for transport, heating or air conditioning. This phenomenon, known as the "urban heat island," has been known for years, but until now has mainly been thought to affect only city dwellers, especially in summer heatwaves.


But a team of scientists in the United States, using a computer model of the atmosphere, point to impacts that go much farther than expected. The high concentration of heat rises into jet-stream winds and widens their flow, transporting heat -- as much as one degree Celsius (1.8 degrees Fahrenheit) -- to places far away. The modelling sees autumn and winter warming across large parts of northern Canada and Alaska and in northern China.


The effect on global temperatures, though, is negligible, accounting for an average warming worldwide of just 0.01 C (0.02 F).

No comment yet.
Scooped by Dr. Stefan Gruenwald!

Evolution inspires more efficient solar cell design: Geometric pattern maximizes time light is trapped in solar cell

Evolution inspires more efficient solar cell design: Geometric pattern maximizes time light is trapped in solar cell | Amazing Science |

The sun's energy is virtually limitless, but harnessing its electricity with today's single-crystal silicon solar cells is extremely expensive—10 times pricier than coal, according to some estimates. Organic solar cells—polymer solar cells that use organic materials to absorb light and convert it into electricity—could be a solution, but current designs suffer because polymers have less-than-optimal electrical properties. Ads by Google San Diego Solar Panels - USA-Made Solar Panels For $0 Down. High Efficiency. Low Cost. Save Now -


Researchers at Northwestern University have now developed a new design for organic solar cells that could lead to more efficient, less expensive solar power. Instead of attempting to increase efficiency by altering the thickness of the solar cell's polymer layer—a tactic that has preciously garnered mixed results—the researchers sought to design the geometric pattern of the scattering layer to maximize the amount of time light remained trapped within the cell. Using a mathematical search algorithm based on natural evolution, the researchers pinpointed a specific geometrical pattern that is optimal for capturing and holding light in thin-cell organic solar cells. The resulting design exhibited a three-fold increase over the Yablonovitch Limit, a thermodynamic limit developed in the 1980s that statistically describes how long a photon can be trapped in a semiconductor.

No comment yet.
Scooped by Dr. Stefan Gruenwald!

Direct Mapping of Data: Unified Internet of Knowledge by 2022

Direct Mapping of Data: Unified Internet of Knowledge by 2022 | Amazing Science |

The 256 bit unified processor and memory system will turn world computer architecture and the Internet upside down in the year 2022.

For the first time in human history, one logical computer will be able to directly address every bit and byte of memory and every device on the Internet. In effect, it will gain direct access to all stored human knowledge.

One major benefit is the lack of duplication required - every computer operating system, every software version, every video, every piece of music, every web site, and bit of information about the world and it's inhabitants is there. No need to distribute videos or music anymore - carefully positioned local cache's across the world will provide enough resilience and high speed access to all information anywhere.

Machine to machine communication will be direct. The 128 bit addresses of IPv6, which allow 4.8×10E28 individual addresses on the Internet, would be a very small subset of the 256 bit address space. Not only would individual devices be online as now, but it will be possible to map device memory and address that directly - in effect writing content directly to a TV screen, an MP3 player, your watch, and maybe even your brain.

With direct access also comes the ability to promote knowledge - medical history, geo data, dietary consumption, personal addictions, communications, and much more can be cross referenced, correlated, and eventually understood. The addressing scheme easily allows storage and access to every human beings genome for example, in both raw and encoded formats.

Having every bit of information in the world allows direct access to whole new universes of knowledge, along with equally massive security concerns. However, we have 10 years to design an architecture that will provide such massive potential pooling of knowledge and removal of duplication that we can afford to spend the resource to ensure it is much more secure than the existing Internet, with it's clouds of "bots" and counter-counter cyber terrorists.

In terms of communications and entertainment, mapping together the video and audio inputs and outputs would allow for example mass video conferences and broadcasts. Millions of people can't speak at the same time, but all can watch an election candidate for example and interact in real time.

No comment yet.
Scooped by Dr. Stefan Gruenwald!

Reprogammed induced pluripotent stem cells are not rejected by immune system

Reprogammed induced pluripotent stem cells are not rejected by immune system | Amazing Science |
Researchers uncover more evidence that reprogrammed stem cells are not attacked by the immune system, suggesting they may one day serve as effective therapies.


Because iPSCs can be derived from a patient’s own tissues, researchers believed that transplantation into that patient should not provoke an immune response. But in 2011, Yang Xu’s team at the University of California, San Diego, called such assumptions into question when they provided evidence that iPSCs derived from mice were attacked and rejected by the immune system when implanted into genetically identical mice.


This prompted Ashleigh Boyd and colleagues at Boston University Medical School to try a similar experiment themselves. They differentiated mouse-derived iPSCs into three different cell lines with two different methods and assessed the immune response, both in vitro and after transplantation into genetically identical mice. They found no evidence that white blood cell count increased in vitro, nor of immune rejection in the transplant experiments.

The researchers concede that the discrepancy between their results and Xu’s findings may result from transplanting the cells into different parts of the body. Nevertheless, they wrote, “our data support the idea that differentiated cells generated from autologous iPSCs could be applied for cell replacement therapy without eliciting immune rejection.”

No comment yet.