Amazing Science
Follow
333.6K views | +157 today
Scooped by Dr. Stefan Gruenwald
onto Amazing Science
Scoop.it!

Super-sensory hearing? Newly identified hearing organ in bushcrickets' ears may inspire acoustic sensors

Super-sensory hearing? Newly identified hearing organ in bushcrickets' ears may inspire acoustic sensors | Amazing Science | Scoop.it

The discovery of a previously unidentified hearing organ in the South American bushcrickets' ear could pave the way for technological advancements in bio-inspired acoustic sensors research, including medical imaging and hearing aid development.

 

Researchers from the University of Bristol and University of Lincoln discovered the missing piece of the jigsaw in the understanding of the process of energy transformation in the 'unconventional' ears of the bushcrickets (or katydids).


Bushcrickets have four tympana (or ear drums) -- two on each foreleg; but until now it has been unknown how the various organs connect in order for the insect to hear. As the tympana (a membrane which vibrates in reaction to sound) does not directly connect with the mechanoreceptors (sensory receptors), it was a mystery how sound was transmitted from air to the mechano-sensory cells.


Sponsored by the Human Frontiers Science Program (HFSP), the research was developed in the lab of Professor Daniel Robert, a Royal Society Fellow at the University of Bristol. Dr Fernando Montealegre-Z, who is now at the University of Lincoln's School of Life Sciences, discovered a newly identified organ while carrying out research into how the bushcricket tubing system in the ear transports sound. The research focussed on the bushcricket Copiphora gorgonensis, a neotropical species from the National Park Gorgona in Colombia, an island in the Pacific. Results suggest that the bushcricket ear operates in a manner analogous to that of mammals. Dr. Montealegre-Z said: "We discovered a novel structure that constitutes the key element in hearing in these insects, which had not been considered in previous work. The organ is a fluid-filled vesicle, which we have named the 'Auditory Vesicle'. This hearing organ mediates the process of conversion of acoustic energy (sound waves) to mechanical, hydraulic and electrochemical energy. The integration laser Doppler vibrometry and micro-CT scanning allowed us to identify the auditory vesicle and to conclude that the process relies on a tympanal lever system analogous to the mammalian ossicles. This serves to transmit air-borne vibrations to the fluid (the auditory vesicle), and also on the mechanoreceptors. Therefore the bushcricket ear performs the crucial stage of air to liquid impedance conversion and amplification just as in a mammal's ear."

more...
No comment yet.
Your new post is loading...
Scooped by Dr. Stefan Gruenwald
Scoop.it!

20,000+ FREE Online Science and Technology Lectures from Top Universities

20,000+ FREE Online Science and Technology Lectures from Top Universities | Amazing Science | Scoop.it

NOTE: To subscribe to the RSS feed of Amazing Science, copy http://www.scoop.it/t/amazing-science/rss.xml into the URL field of your browser and click "subscribe".

 

This newsletter is aggregated from over 1450 news sources:

http://www.genautica.com/links/1450_news_sources.html

 

All my Tweets and Scoop.It! posts sorted and searchable:

http://www.genautica.com/tweets/index.html

 

••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••

You can search through all the articles semantically on my

archived twitter feed

••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••

NOTE: All articles in the amazing-science newsletter can also be sorted by topic. To do so, click the FIND buntton (symbolized by the FUNNEL on the top right of the screen)  and display all the relevant postings SORTED by TOPICS.

 

You can also type your own query:

 

e.g., you are looking for articles involving "dna" as a keyword

 

http://www.scoop.it/t/amazing-science/?q=dna


Or CLICK on the little FUNNEL symbol at the top right of the screen

••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••


MOST_READ • 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 

more...
Casper Pieters's curator insight, March 9, 4:21 PM

Great resources for online learning just about everything.  All you need is will power and self- discipline.

Russ Roberts's curator insight, April 23, 8:37 PM

A very interesting site.  Amazing Science covers many disciplines.  Subscribe to the news letter and be " amazed." Aloha, Russ, KH6JRM. 

Siegfried Holle's curator insight, July 4, 5:45 AM

Your knowledge is your strength and power 

Scooped by Dr. Stefan Gruenwald
Scoop.it!

Powerful new sensor identfies molecules containing fewer than 20 atoms

Powerful new sensor identfies molecules containing fewer than 20 atoms | Amazing Science | Scoop.it

Researchers at Rice University’s Laboratory for Nanophotonics (LANP) have created a unique sensor that amplifies the optical signature of molecules by about 100 billion times — accurately identifying the composition and structure of individual molecules containing fewer than 20 atoms.


The new single-molecule imaging method, described  in the journal Nature Communications, uses a form of Raman spectroscopy in combination with optical amplifier, making the sensor about 10 times more powerful that previously reported devices, said LANP Director Naomi Halas, the lead scientist on the study.


“The ideal single-molecule sensor would be able to identify an unknown molecule — even a very small one — without any prior information about that molecule’s structure or composition. That’s not possible with current technology, but this new technique has that potential.”


The optical sensor uses Raman spectroscopy, a technique pioneered in the 1930s that blossomed after the advent of lasers in the 1960s. When light strikes a molecule, most of its photons bounce off or pass directly through, but a tiny fraction — fewer than one in a trillion — are absorbed and re-emitted into another energy level that differs from their initial level. By measuring and analyzing these re-emitted photons through Raman spectroscopy, scientists can decipher the types of atoms in a molecule as well as their structural arrangement.


Scientists have created a number of techniques to boost Raman signals. In the new study, LANP graduate student Yu Zhang used one of these, a two-coherent-laser technique called “coherent anti-Stokes Raman spectroscopy,” or CARS. By using CARS in conjunction with a light amplifier made of four tiny gold nanodiscs, Halas and Zhang were able to measure single molecules in a powerful new way. LANP has dubbed the new technique “surface-enhanced CARS,” or SECARS.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Noninvasive retinal imaging device detects Alzheimer’s up to 20 years in advance

Noninvasive retinal imaging device detects Alzheimer’s up to 20 years in advance | Amazing Science | Scoop.it

Cedars-SinaI Medical Center researchers have developed a noninvasive retinal imaging device that can provide early detection of changes indicating Alzheimer’s disease 15 to 20 years before clinical diagnosis.


“In preliminary results in 40 patients, the test could differentiate between Alzheimer’s disease and non-Alzheimer’s disease with 100 percent sensitivity and 80.6 percent specificity, meaning that all people with the disease tested positive and most of the people without the disease tested negative,” said Shaun Frost, a biomedical scientist and the study manager at the Commonwealth Scientific and Industrial Research Organisation (CSIRO), Australia’s national science agency.


Keith Black, MD, professor and chair of Cedars-Sinai’s Department of Neurosurgery and director of the Maxine Dunitz Neurosurgical Institute and the Ruth and Lawrence Harvey Chair in Neuroscience, said the accumulation of beta-amyloid plaque in the brain is a hallmark sign of Alzheimer’s, but current tests detect changes only after the disease has advanced to late stages.


Researchers believe that as treatment options improve, early detection will be critical, but existing diagnostic methods are inconvenient, costly and impractical for routine screening.


“PET scans require the use of radioactive tracers, and cerebrospinal fluid analysis requires that patients undergo invasive and often painful lumbar punctures, but neither approach is quite feasible, especially for patients in the earlier stages of disease,” he said. Positron emission tomography, or PET, is the current diagnostic standard.


“The retina, unlike other structures of the eye, is part of the central nervous system, sharing many characteristics of the brain. A few years ago, we discovered at Cedars-Sinai that the plaques associated with Alzheimer’s disease occur not only in the brain but also in the retina.


more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Better use of world’s existing cropland could feed 3 billion more people, study shows

Better use of world’s existing cropland could feed 3 billion more people, study shows | Amazing Science | Scoop.it

Research reveals large increases in population expected in the next three decades need not result in widespread hunger.


The world’s existing cropland could feed at least 3 billion extra people if it were used more efficiently, a new study has found, showing that the large increases in population expected in the next three decades need not result in widespread hunger.


More than half of the fertiliser currently poured on to crops in many countries is wasted, according to the study. About 60% of the nitrogen applied to crops worldwide is not needed, as well as about half of the phosphorus, an element whose readily available sources are dwindling.


Cutting waste even by modest amounts would also feed millions, the authors found: between one-third and a half of the viable crops and food produced from them around the world are wasted, in the developing world usually because of a lack of infrastructure such as refrigerated transport, and in the rich world because of wasteful habits.


The study, published in the peer-review journal Science and led by scientists at the University of Minnesota in the US, suggested that a focus on staple crops such as wheat and rice in key countries, including China, India, the US, Brazil, Indonesia, Pakistan and Europe, would pay off in terms of producing more food for the world’s growing population. Most forecasts are that the world will number more than 9 billion people by 2050, up from about 7 billion people today.


Looking after water could also yield vast dividends, the report found: if the water used for irrigation was pinpointed more efficiently to where it is needed, then much more could be grown, but currently much of it is sprayed uselessly over crops. Between 8% and 15% of the water currently used could be saved, the study suggested.


But the research also found that at least 4 billion people could be fed with the crops we currently devote to fattening livestock, fuelling the argument that the over-reliance on meat in the west and among the growing middle classes in the developing world is an increasing problem when it comes to feeding the world.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

MED12: Genetic cause of common breast tumors (fibroadenomas) found

MED12: Genetic cause of common breast tumors (fibroadenomas) found | Amazing Science | Scoop.it
A major breakthrough in understanding the molecular basis of fibroadenoma, one of the most common breast tumors diagnosed in women, has been made by a multidisciplinary team of scientists. The team used advanced DNA sequencing technologies to identify a critical gene called MED12 that was repeatedly disrupted in nearly 60 percent of fibroadenoma cases.


A multi-disciplinary team of scientists from the National Cancer Centre Singapore, Duke-NUS Graduate Medical School Singapore, and Singapore General Hospital have made a major breakthrough in understanding the molecular basis of fibroadenoma, one of the most common breast tumors diagnosed in women. The team, led by Professors Teh Bin Tean, Patrick Tan, Tan Puay Hoon and Steve Rozen, used advanced DNA sequencing technologies to identify a critical gene called MED12 that was repeatedly disrupted in nearly 60% of fibroadenoma cases. Their findings have been published in the top-ranked journal Nature Genetics.


Fibroadenomas are the most common benign breast tumors in women of reproductive age, affecting thousands of women in Singapore each year. Worldwide, it is estimated that millions of women are diagnosed with fibroadenoma annually. Frequently discovered in clinical workups for breast cancer diagnosis and during routine breast cancer screening, clinicians often face of challenge of distinguishing fibroadenomas from breast cancer.


To facilitate this diagnostic question, the team embarked on a study to identify if there are any genetic abnormalities in fibroadenomas that may be used to differentiate them. By analysing all the protein-coding genes in a panel of fibroadenomas from Singapore patients, the team identified frequent mutations in a gene called MED12 in a remarkable 60% of fibroadenomas. Prof Tan Puay Hoon said, "It is amazing that these common breast tumors can be caused by such a precise disruption in a single gene. Our findings show that even common diseases can have a very exact genetic basis. Importantly, now that we know the cause of fibroadenoma, this research can have many potential applications."


Prof Tan added, "For example, measuring the MED12 gene in breast lumps may help clinicians to distinguish fibroadenomas from other types of breast cancer. Drugs targeting the MED12 pathway may also be useful in patients with multiple and recurrent fibroadenomas as this could help patients avoid surgery and relieve anxiety."


The team's findings have also deepened the conceptual understanding of how tumors can develop. Like most breast tumors including breast cancers, fibroadenomas consist of a mixed population of different cell types, called epithelial cells and stromal cells. However, unlike breast cancers where the genetic abnormalities arise from the epithelial cells, the scientists, using a technique called laser capture microdissection (LCM), showed that the pivotal MED12 mutations in fibroadenomas are found in the stromal cells.


Reference:

  1. Weng Khong Lim, Choon Kiat Ong, Jing Tan, Aye Aye Thike, Cedric Chuan Young Ng, Vikneswari Rajasegaran, Swe Swe Myint, Sanjanaa Nagarajan, Nur Diyana Md Nasir, John R McPherson, Ioana Cutcutache, Gregory Poore, Su Ting Tay, Wei Siong Ooi, Veronique Kiak Mien Tan, Mikael Hartman, Kong Wee Ong, Benita K T Tan, Steven G Rozen, Puay Hoon Tan, Patrick Tan, Bin Tean Teh. Exome sequencing identifies highly recurrent MED12 somatic mutations in breast fibroadenomaNature Genetics, 2014; DOI: 10.1038/ng.3037


more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Propellantless propulsion with Electric solar wind sail for cheaper and faster space missions

Propellantless propulsion with Electric solar wind sail for cheaper and faster space missions | Amazing Science | Scoop.it

A paper analyses the potential of the electric solar wind sail for solar system space missions. Applications studied include fly-by missions to terrestrial planets (Venus, Mars and Phobos, Mercury) and asteroids, missions based on non-Keplerian orbits (orbits that can be maintained only by applying continuous propulsive force), one-way boosting to outer solar system, off-Lagrange point space weather forecasting and low-cost impactor probes for added science value to other missions. We also discuss the generic idea of data clippers (returning large volumes of high resolution scientific data from distant targets packed in memory chips) and possible exploitation of asteroid resources. Possible orbits were estimated by orbit calculations assuming circular and coplanar orbits for planets. Some particular challenge areas requiring further research work and related to some more ambitious mission scenarios are also identified and discussed.

The electric solar wind sail (E-sail) is an advanced concept for spacecraft propulsion, based on momentum transfer from the solar wind plasma stream, intercepted by long and charged tethers. The electrostatic field created by the tethers deflects trajectories of solar wind protons so that their flow-aligned momentum component decreases. The flow-aligned momentum lost by the protons is transferred to the charged tether by a Coulomb force (the charged tether is pulled by the plasma charge separation electric field) and then transmitted to the spacecraft as thrust. The concept is attractive for applications because no propellant is needed for traveling over long distances. The E-sail’s operating principle is different from other propellantless propulsion technologies such as the solar photon sail and the solar wind magnetic sail. The former is based on momentum transfer from sunlight (solar photons), while the latter is based on a large loop-shaped superconductive wire whose magnetic field deflects solar wind protons from their originally straight trajectories.


The main purpose of this article is to analyze the potential of E-sail technology in some of the envisaged possible applications for solar system space activities. To a limited extent we also adopt a comparative approach,estimating the added value and other advantages stemming from E-sail technology in comparison with present chemical and electric propulsion systems and(in some cases) with other propellantless propulsion concepts. When making such comparisons a key quantity that we use for representing the mission cost is the total required velocity change, Av, also called delta-v.The Sail Propulsion Working Group, a joint working group between the Navigation Guidance and Control Section and the Electric Propulsion Section of the European Space Agency, has envisaged the study of three reference missions which could be successfully carried out using propellantless propulsion concepts.


Even more advanced solar electric space sail configurations were explored in several previous electric sail papers.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

NASA: Ocean on Saturn Moon Could be as Salty as the Dead Sea

NASA: Ocean on Saturn Moon Could be as Salty as the Dead Sea | Amazing Science | Scoop.it

Scientists analyzing data from NASA’s Cassini mission have firm evidence the ocean inside Saturn's largest moon, Titan, might be as salty as Earth's Dead Sea.


The new results come from a study of gravity and topography data collected during Cassini's repeated flybys of Titan during the past 10 years. Using the Cassini data, researchers presented a model structure for Titan, resulting in an improved understanding of the structure of the moon's outer ice shell. The findings are published in this week’s edition of the journal Icarus.


"Titan continues to prove itself as an endlessly fascinating world, and with our long-lived Cassini spacecraft, we’re unlocking new mysteries as fast as we solve old ones," said Linda Spilker, Cassini project scientist at NASA's Jet Propulsion Laboratory in Pasadena, California, who was not involved in the study.


Additional findings support previous indications the moon's icy shell is rigid and in the process of freezing solid. Researchers found that a relatively high density was required for Titan's ocean in order to explain the gravity data. This indicates the ocean is probably an extremely salty brine of water mixed with dissolved salts likely composed of sulfur, sodium and potassium. The density indicated for this brine would give the ocean a salt content roughly equal to the saltiest bodies of water on Earth.


"This is an extremely salty ocean by Earth standards," said the paper's lead author, Giuseppe Mitri of the University of Nantes in France. "Knowing this may change the way we view this ocean as a possible abode for present-day life, but conditions might have been very different there in the past."


Cassini data also indicate the thickness of Titan's ice crust varies slightly from place to place. The researchers said this can best be explained if the moon's outer shell is stiff, as would be the case if the ocean were slowly crystalizing and turning to ice. Otherwise, the moon's shape would tend to even itself out over time, like warm candle wax. This freezing process would have important implications for the habitability of Titan's ocean, as it would limit the ability of materials to exchange between the surface and the ocean.


A further consequence of a rigid ice shell, according to the study, is any outgassing of methane into Titan's atmosphere must happen at scattered "hot spots" -- like the hot spot on Earth that gave rise to the Hawaiian Island chain. Titan's methane does not appear to result from convection or plate tectonics recycling its ice shell.


How methane gets into the moon's atmosphere has long been of great interest to researchers, as molecules of this gas are broken apart by sunlight on short geological timescales. Titan's present atmosphere contains about five percent methane. This means some process, thought to be geological in nature, must be replenishing the gas. The study indicates that whatever process is responsible, the restoration of Titan's methane is localized and intermittent.


"Our work suggests looking for signs of methane outgassing will be difficult with Cassini, and may require a future mission that can find localized methane sources," said Jonathan Lunine, a scientist on the Cassini mission at Cornell University, Ithaca, New York, and one of the paper's co-authors. "As on Mars, this is a challenging task."

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Supercomputers reveal strange, stress-induced transformations in world's thinnest materials

Supercomputers reveal strange, stress-induced transformations in world's thinnest materials | Amazing Science | Scoop.it

Interested in an ultra-fast, unbreakable, and flexible smart phone that recharges in a matter of seconds? Monolayer materials may make it possible. These atom-thin sheets—including the famed super material graphene—feature exceptional and untapped mechanical and electronic properties. But to fully exploit these atomically tailored wonder materials, scientists must pry free the secrets of how and why they bend and break under stress.

Fortunately, researchers have now pinpointed the breaking mechanism of several monolayer materials hundreds of times stronger than steel with exotic properties that could revolutionize everything from armor to electronics. A Columbia University team used supercomputers at the U.S. Department of Energy's Brookhaven National Laboratory to simulate and probe quantum mechanical processes that would be extremely difficult to explore experimentally.


They discovered that straining the materials induced a novel phase transition—a restructuring in their near-perfect crystalline structures that leads to instability and failure. Surprisingly, the phenomenon persisted across several different materials with disparate electronic properties, suggesting that monolayers may have intrinsic instabilities to be either overcome or exploited. The results were published in the journal Physical Review B.


"Our calculations exposed these monolayer materials' fundamental shifts in structure and character when stressed," said study coauthor and Columbia University Ph.D. candidate Eric Isaacs. "To see the beautiful patterns exhibited by these materials at their breaking points for the first time was enormously exciting—and important for future applications."

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Crystal structure of one of the most complex ternary complexes in cell division, important to cancer

Crystal structure of one of the most complex ternary complexes in cell division, important to cancer | Amazing Science | Scoop.it

Research carried out at the ICR has revealed the structure of one of the most important and complicated proteins in cell division – a fundamental process the development of cancer, published in Nature.


Images of the gigantic protein in unprecedented detail will transform scientists’ understanding of exactly how cells copy their chromosomes and divide, and could reveal binding sites for future cancer drugs.


A team from The Institute of Cancer Research, London, and the Medical Research Council Laboratory of Molecular Biology in Cambridge produced the first detailed images of the anaphase-promoting complex (APC/C).


The APC/C performs a wide range of vital tasks associated with mitosis, the process during which a cell copies its chromosomes and pulls them apart into two separate cells. Mitosis is used in cell division by all animals and plants.


Discovering its structure could ultimately lead to new treatments for cancer, which hijacks the normal process of cell division to make thousands of copies of harmful cancer cells.


In the study, which was funded by Cancer Research UK, the researchers reconstituted human APC/C and used a combination of electron microscopy and imaging software to visualize it at a resolution of less than a nanometer.


The resolution was so fine that it allowed the researchers to see the secondary structure – the set of basic building blocks which combine to form every protein. Alpha-helix rods and folded beta-sheet constructions were clearly visible within the 20 subunits of the APC/C, defining the overall architecture of the complex.


Previous studies led by the same research team had shown a globular structure for APC/C in much lower resolution, but the secondary structure had not previously been mapped. The new study could identify binding sites for potential cancer drugs.


Each of the APC/C’s subunits bond and mesh with other units at different points in the cell cycle, allowing it to control a range of mitotic processes including the initiation of DNA replication, the segregation of chromosomes along protein ‘rails’ called spindles, and the ultimate splitting of one cell into two, called cytokinesis. Disrupting each of these processes could selectively kill cancer cells or prevent them from dividing.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Cystic Fibrosis Might Actually Consist of Two Different Diseases

Cystic Fibrosis Might Actually Consist of Two Different Diseases | Amazing Science | Scoop.it

The sister disease affects the pancreas and other organs, while leaving the lungs alone.


Thick mucus that can drown the lungs of a child has long been the hallmark of cystic fibrosis. The hereditary disease affects 30,000 Americans, and patients die unless they receive treatment to clear their lungs. But new research suggests that this pulmonary view of cystic fibrosis is only half of the picture: a suite of symptoms associated with cystic fibrosis can also occur in patients who do not have lung disease at all, indicating that cystic fibrosis is really two diseases. This second version, it appears, causes pancreatitis.


"Cystic fibrosis has been evaluated and managed by pulmonary doctors focusing on the lung, but other important problems are never seen by the pulmonologist and nobody's put the pieces together," says David Whitcomb of the University of Pittsburgh, who studies disorders of the pancreas.


Cystic fibrosis results from mutations in a gene that produces a tube-shaped protein known as CFTR, essential to the balance of electrolytes in the body. Specifically, this protein allows chloride ions to pass in and out of cells. When it malfunctions in classic cystic fibrosis, cells in the airway cannot produce normal mucus but instead make a thicker, stickier substance that clogs the lungs.


But CFTR leads a double life. Whitcomb's team screened a group of nearly 1,000 patients with pancreatitis and found nine abnormal but supposedly harmless versions of the CFTR gene. Their study suggests that the seemingly benign mutations break the switch that turns CFTR from a chloride portal to a channel for bicarbonate, a chemical that the pancreas produces to neutralize stomach acid. Patients with these mutations do not have the problems associated with the chloride channel, but the faulty bicarbonate channel means that they can suffer from painful pancreatitis, as well as sinusitis and, in men, infertility. Computer simulations confirmed that the mutations are all in places that would inhibit bicarbonate but not chloride from passing through.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

First time transplantation of inhibitory neuron progenitor cells reverses memory loss in Alzheimer's disease model

First time transplantation of inhibitory neuron progenitor cells reverses memory loss in Alzheimer's disease model | Amazing Science | Scoop.it
A new study has revealed a way to alleviate the learning and memory deficits caused by apoE4, the most important genetic risk factor for Alzheimer's disease, improving cognition to normal levels in aged mice. The success of the treatment in older mice, which corresponded to late adulthood in humans, is particularly important, as this would be the age that would be targeted were this method ever to be used therapeutically in people.


In the study, which was conducted in collaboration with researchers at UC San Francisco and published today in the Journal of Neuroscience, scientists transplanted inhibitory neuron progenitors -- early-stage brain cells that have the capacity to develop into mature inhibitory neurons -- into two mouse models of Alzheimer's disease, apoE4 or apoE4 with accumulation of amyloid beta, another major contributor to Alzheimer's. The transplants helped to replenish the brain by replacing cells lost due to apoE4, regulating brain activity and improving learning and memory abilities.


"This is the first time transplantation of inhibitory neuron progenitors has been used in aged Alzheimer's disease models," said first author Leslie Tong, a graduate student at the Gladstone Institutes and UCSF. "Working with older animals can be challenging from a technical standpoint, and it was amazing to see that the cells not only survived but affected activity and behavior."


The success of the treatment in older mice, which corresponded to late adulthood in humans, is particularly important, as this would be the age that would be targeted were this method ever to be used therapeutically in people.


"This is a very important proof of concept study," said senior author Yadong Huang, MD, PhD, an associate investigator at Gladstone Institutes and associate professor of neurology and pathology at UCSF. "The fact that we see a functional integration of these cells into the hippocampal circuitry and a complete rescue of learning and memory deficits in an aged model of Alzheimer's disease is very exciting."

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

A noble gas cage: New material traps gases from nuclear fuel better

A noble gas cage: New material traps gases from nuclear fuel better | Amazing Science | Scoop.it

When nuclear fuel gets recycled, the process releases radioactive krypton and xenon gases. Naturally occurring uranium in rock contaminates basements with the related gas radon. A new porous material called CC3 effectively traps these gases, and research appearing July 20 in Nature Materials shows how: by breathing enough to let the gases in but not out.

The CC3 material could be helpful in removing unwanted or hazardous radioactive elements from nuclear fuel or air in buildings and also in recycling useful elements from the nuclear fuel cycle. CC3 is much more selective in trapping these gases compared to other experimental materials. Also, CC3 will likely use less energy to recover elements than conventional treatments, according to the authors.


The team made up of scientists at the University of Liverpool in the U.K., the Department of Energy's Pacific Northwest National Laboratory, Newcastle University in the U.K., and Aix-Marseille Universite in France performed simulations and laboratory experiments to determine how—and how well—CC3 might separate these gases from exhaust or waste.

"Xenon, krypton and radon are noble gases, which are chemically inert. That makes it difficult to find materials that can trap them," said coauthor Praveen Thallapally of PNNL. "So we were happily surprised at how easily CC3 removed them from the gas stream."


Noble gases are rare in the atmosphere but some such as radon come in radioactive forms and can contribute to cancer. Others such as xenon are useful industrial gases in commercial lighting, medical imaging and anesthesia.


The conventional way to remove xenon from the air or recover it from nuclear fuel involves cooling the air far below where water freezes. Such cryogenic separations are energy intensive and expensive. Researchers have been exploring materials called metal-organic frameworks, also known as MOFs, that could potentially trap xenon and krypton without having to use cryogenics. Although a leading MOF could remove xenon at very low concentrations and at ambient temperatures admirably, researchers wanted to find a material that performed better.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Intestinal bacterial ecosystem: Identification of 741 bacteria, 181 new species, and 848 bacterial viruses

Intestinal bacterial ecosystem: Identification of 741 bacteria, 181 new species, and 848 bacterial viruses | Amazing Science | Scoop.it

Researchers at DTU (Technical University of Denmark) in collaboration with an international team from countries including France and China devised a method based on the co-abundance principle to easily identify the genomes (or genetic material) of unknown intestinal microorganisms. The scientists demonstrated this method on 396 human stool samples and uncovered 741 microbial species of which 181 are proposed to be completely novel.  Unlike prior methods to identify bacterial species, the use of CAGs obviates the need for assembly as well the need for a database of reference genomes.


The new approach also identified 848 viruses that infect each bacterium (called bacteriophages). The balance of intestinal fauna affects human health as it is increasingly recognized disrupting such balance for example by use of antibiotics leads to disease states.  Therefore modulation of the bacterial composition by viral agents is an attractive means to restore the balance.  Moreover, the new insight makes possible the exploitation of viruses to attack specific bacteria, thereby adding another tool to our pharmacological arsenal which is under increasing pressure from antibiotic resistance.


The human intestine is home to many microorganisms, whose cell population is estimated to be 10 times greater than the number of human cells in an individual.  Only a few species that can be cultivated in the laboratory to be sequenced by traditional methods.  Identification of the different microbial species in the intestinal ecology and their interactions will lead to better understanding of relevant disease conditions such as type 2 diabetes, asthma and obesity.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

CRISPR: the next generation of genome editing tools

CRISPR: the next generation of genome editing tools | Amazing Science | Scoop.it

An arms race has been waged between bacteria and bacteriophage that would bring a satisfactory tear to Sun Tzu’s eye. Scientists have recently recognized that countermeasures developed by bacteria (and archaea) in response to phage infections can be retooled for use within molecular biology. In 2013, large strides have been made to co-opt this system (specifically and most commonly from Streptococcus pyogenes) for use in mammalian cells. This countermeasure, CRISPR (clustered regularly interspaced short palindromic repeats), has brought about another successive wave of genome engineering initiated by recombineering and followed more recently by zinc finger nucleases (ZFNs) and transcription activator-like effector nucleases (TALENs).


ZFNs and TALENs perform a similar function yet the learning curve appears to be more difficult for development due to the use of protein-DNA contacts rather than the simplicity of designing RNA-DNA homology contacts. Although the potential for CRISPR in regards to genome editing within mammalian cells will be of greatest interest to the reader, the CRISPR backstory is equally compelling. Just as we have evolved immune responses to pathogens, so too have bacteria. CRISPR is an adapted immune response evolved by bacteria to create an immunological memory to ward off future phage infections. When a phage infects and injects its DNA within a bacterium, the DNA commandeers bacterial proteins and enzymes for use towards lytic or lysogenic phases. However, exposure of phage DNA allows the bacterium to copy and insert snippets (called spacers) of phage DNA into its genomic DNA between direct repeats (DR). These snippets can later be expressed as an operon (pre-CRISPR RNA, pre-crRNA) alongside a trans-activating CRISPR RNA (tracrRNA) and an effector CRISPR associated nuclease (Cas). Together these components surveil for foreign crRNA cognate sequence and cleave the targeted sequence.


Although hallmarks of CRISPR have been known since the late 80’s (CRISPR timeline) and was acronymed in 2002, Jinek et al. in August 2012 were the first to suggest the suitability of CRISPR towards genome editing. In February of 2013, Feng Zhang’s and George Church’s labs simultaneously published the first papers describing the use long oligos/constructs for editing via CRISPR in mammalian cells and made their plasmids readily available on Addgene. Zhang’s lab went one step further and has supplemented their papers with a helpful website and user forum. They have even gone so far as to publish a methods paper to streamline the use of their plasmids towards a plug-and-play, modular cloning approach with your target sequence of interest.


CRISPR works fairly well out of the box yet still has some imperfections that are being addressed. For example, CRISPR relies upon a protospacer adjacent motif (PAM; S. pyogenes sequence: NGG) 3’ to the targeting sequence to permit digestion. Although the ubiquity of NGG within the genome may seem advantageous, it may be limiting in some regions. Other species make use of different PAM sites that can be considered when choosing a cut sites of interest. Since double-stranded cuts could potentially create DNA lesions (a byproduct of the cell using non-homologous end joining [NHEJ] instead of homologous recombination) some labs are choosing to use modified Cas enzymes that nick DNA, instead of creating a double-strand break. This potential weakness of CRISPR to create DNA lesions via NHEJ, however, has been exploited by Eric Lander’s and Zhang’s lab this month (Jan. 2014). They have capitalized on the cell’s use of NHEJ to manufacture DNA lesions (frameshift mutations) at cut sites within genes on a large scale as a means to perform large genetic screens. Using this technique knocks out a gene and has the obvious advantage of fully ablating a gene’s expression compared to RNAi where some residual expression can be expected.


The advantages of CRISPR lends itself to future therapies. High efficiency, low-to-no background mutagenesis and easy construction put CRISPR front and center as the tool de jour for gene therapy. In combination with induced pluripotent stem cells (iPSCs), one can imagine the creation of patient-specific iPSCs created with non-integrative iPSC vectors and modified by CRISPR, devoid of any residual DNA footprint left behind by the iPSC vector or CRISPR correction. In conjunction with whole genome sequencing, genetically clean cell lines can be selected that are suitable for differentiation towards the germ layer of interest for subsequent autologous transplantation. Proof of principle experiments have already been published in models of cystic fibrosis and cataracts.


For better or worse, CRISPR is catching on like wildfire with young investigators, as noted recently by Michael Eisen. What may be looming in the future and not as openly discussed at this time is the potential for CRISPR to open up the genome to large scale editing. We tend to think of any particular genome as fairly static with slight variations between any two individuals and increased variation down the evolutionary line. However, CRISPR has proven to be a fantastic multitasker, capable of modifying multiple loci in one fell swoop as demonstrated by the Jaenisch lab (five loci). With the creation of Caribou Biosciences and a surprising round of venture capital raised by a powerhouse team at Editas Medicine in November ($43 million), CRISPR appears to also have sparked an interest in the private sector. With large sums of money at their disposal, these companies can now begin to look at the genome, not as a static entity, but more akin to operating system, a code that now has a facile editing tool. George Church, an Editas co-founder, has speculated in the past about the potential use of the human genome as the backbone for recreating the Neanderthal genome in his recent book and interview with "Der Spiegel". In an era where the J. Craig Venter Institute can create an organism’s genome de novo and a collaboration between Synthetic Genomics and Integrated DNA Technologies has proposed to synthesize DNA upwards of 2Mbp, the combination of CRISPR, synthetic DNA and some elbow grease will make the genome more accessible and Church’s speculations a potential reality.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

3D-printing may revolutionize medical education

3D-printing may revolutionize medical education | Amazing Science | Scoop.it

A kit of 3D-printed anatomical body parts could revolutionize medical education and training, according to its developers at Monash University.

Professor Paul McMenamin, Director of the University’s Centre for Human Anatomy Education, said the simple and cost-effective anatomical kit would dramatically improve trainee doctors’ and other health professionals’ knowledge and could even contribute to the development of new surgical treatments.


“Many medical schools report either a shortage of cadavers, or find their handling and storage too expensive as a result of strict regulations governing where cadavers can be dissected,” he said.


“Without the ability to look inside the body and see the muscles, tendons, ligaments, and blood vessels, it’s incredibly hard for students to understand human anatomy. We believe our version, which looks just like the real thing, will make a huge difference.”


The 3D Printed Anatomy Series kit, to go on sale later this year, could have particular impact in developing countries where cadavers aren’t readily available, or are prohibited for cultural or religious reasons.


After scanning real anatomical specimens with either a CT or surface laser scanner, the body parts are 3D printed either in a plaster-like powder or in plastic, resulting in high resolution, accurate color reproductions.


Further details have been published online in the journal Anatomical Sciences Education.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Organogenesis in a dish: Modeling development and disease using organoid technologies

Organogenesis in a dish: Modeling development and disease using organoid technologies | Amazing Science | Scoop.it

Organoids have been generated for a number of organs from both mouse and human stem cells. To date, human pluripotent stem cells have been coaxed to generate intestinal, kidney, brain, and retinal organoids, as well as liver organoid-like tissues called liver buds.


Derivation methods are specific to each of these systems, with a focus on recapitulation of endogenous developmental processes. Specifically, the methods so far developed use growth factors or nutrient combinations to drive the acquisition of organ precursor tissue identity.


Then, a permissive three-dimensional culture environment is applied, often involving the use of extracellular matrix gels such as Matrigel. This allows the tissue to self-organize through cell sorting out and stem cell lineage commitment in a spatially defined manner to recapitulate organization of different organ cell types.


These complex structures provide a unique opportunity to model human organ development in a system remarkably similar to development in vivo. Although the full extent of similarity in many cases still remains to be determined, organoids are already being applied to human-specific biological questions. Indeed, brain and retinal organoids have both been shown to exhibit properties that recapitulate human organ development and that cannot be observed in animal models. Naturally, limitations exist, such as the lack of blood supply, but future endeavors will advance the technology and, it is hoped, fully overcome these technical hurdles.

Outlook: The therapeutic promise of organoids is perhaps the area with greatest potential. These unique tissues have the potential to model developmental disease, degenerative conditions, and cancer. Genetic disorders can be modeled by making use of patient-derived induced pluripotent stem cells or by introducing disease mutations. Indeed, this type of approach has already been taken to generate organoids from patient stem cells for intestine, kidney, and brain.


Furthermore, organoids that model disease can be used as an alternative system for drug testing that may not only better recapitulate effects in human patients but could also cut down on animal studies. Liver organoids, in particular, represent a system with high expectations, particularly for drug testing, because of the unique metabolic profile of the human liver. Finally, tissues derived in vitro could be generated from patient cells to provide alternative organ replacement strategies. Unlike current organ transplant treatments, such autologous tissues would not suffer from issues of immunocompetency and rejection.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Oregon geologist says Curiosity's images show Earth-like soils on Mars

Oregon geologist says Curiosity's images show Earth-like soils on Mars | Amazing Science | Scoop.it

Soil deep in a crater dating to some 3.7 billion years ago contains evidence that Mars was once much warmer and wetter, says University of Oregon geologist Gregory Retallack, based on images and data captured by the rover Curiosity.


NASA rovers have shown Martian landscapes littered with loose rocks from impacts or layered by catastrophic floods, rather than the smooth contours of soils that soften landscapes on Earth. However, recent images from Curiosity from the impact Gale Crater, Retallack said, reveal Earth-like soil profiles with cracked surfaces lined with sulfate, ellipsoidal hollows and concentrations of sulfate comparable with soils in Antarctic Dry Valleys and Chile's Atacama Desert.

His analyses appear in a paper placed online this week by the journal Geology in advance of print in the September issue of the world's top-ranked journal in the field. Retallack, the paper's lone author, studied mineral and chemical data published by researchers closely tied with the Curiosity mission. Retallack, professor ofgeological sciences and co-director of paleontology research at the UO Museum of Natural and Cultural History, is an internationally known expert on the recognition of paleosols — ancient fossilized soils contained in rocks.


"The pictures were the first clue, but then all the data really nailed it," Retallack said. "The key to this discovery has been the superb chemical and mineral analytical capability of the Curiosity Rover, which is an order of magnitude improvement over earlier generations of rovers. The new data show clear chemical weathering trends, and clay accumulation at the expense of the mineral olivine, as expected in soils on Earth. Phosphorus depletion within the profiles is especially tantalizing, because it attributed to microbial activity on Earth."

The ancient soils, he said, do not prove that Mars once contained life, but they do add to growing evidence that an early wetter and warmer Mars was more habitable than the planet has been in the past 3 billion years.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

The Great Filter

The Great Filter | Amazing Science | Scoop.it

The Great Filter, in the context of the Fermi paradox, is whatever prevents "dead matter" from giving rise, in time, to "expanding lasting life" in the universe.[1] The concept originates in Robin Hanson's argument that the failure to find any extraterrestrial civilizations in the observable universe implies the possibility something is wrong with one or more of the arguments from various scientific disciplines that the appearance of advanced intelligent life is probable; this observation is conceptualized in terms of a "Great Filter" which acts to reduce the great number of sites where intelligent life might arise to the tiny number of intelligent species actually observed (currently just one: human). This probability threshold, which could lie behind us (in our past) or in front of us (in our future), might work as a barrier to the evolution of intelligent life, or as a high probability of self-destruction. The main counter-intuitive conclusion of this observation is that the easier it was for life to evolve to our stage, the bleaker our future chances probably are.


The idea was first proposed in an online essay titled, "The Great Filter - Are We Almost Past It?" written by economist Robin Hanson. The first version was written in August 1996 and the article was last updated on September 15, 1998. Since that time, Hanson's formulation has received recognition in several published sources discussing the Fermi paradox and its implications.


According to the Great Filter hypothesis at least one of these steps - if the list were complete - must be improbable. If it's not an early step (i.e. in our past), then the implication is that the improbable step lies in our future and our prospects of reaching step 9 (interstellar colonization) are still bleak. If the past steps are likely, then many civilizations would have developed to the current level of the human race. However, none appear to have made it to step 9, or the Milky Way would be full of colonies. So perhaps step 9 is the unlikely one, and the only thing that appears likely to keep us from step 9 is some sort of catastrophe or the resource exhaustion leading to impossibility to make the step due to consumption of the available resources (like for example highly constrained energy resources). So by this argument, finding multicellular life on Mars (provided it evolved independently) would be bad news, since it would imply steps 2–6 are easy, and hence only 1, 7, 8 or 9 (or some unknown step) could be the big problem.[3]


Although steps 1–7 have occurred on Earth, any one of these may be unlikely. If the first seven steps are necessary preconditions to calculating the likelihood (using the local environment) then an anthropically biased observer can infer nothing about the general probabilities from its (pre-determined) surroundings.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Futuristic fusion reactors could make carbon-free power as early as 2019

Futuristic fusion reactors could make carbon-free power as early as 2019 | Amazing Science | Scoop.it

Dr. David Kirtley comes across as a smart, practical guy with a head for business. That creates some cognitive dissonance when he explains that his Redmond startup is developing fusion energy.


You’ve heard about fusion energy, the amazing power source of the future. Nuclear scientists promise fusion will have all the best qualities of conventional nuclear and natural-gas energy but none of the downsides. Fusion is carbon-free like today’s atomic power, but without the need to protect a thousand future generations from radioactive waste. Other than being mind-blowing, fusion would be relatively safe — no China Syndrome, no contamination, no weapons-grade materials to proliferate.


Thus far, fusion energy always has been an unfinished science that’s 50 years and $50 billion from commercialization. Seven nations are collaborating to build an experimental fusion reactor in France as an $11 billion proof of concept that still won’t produce electricity when it’s operational in 2027.


Dr. Kirtley’s company Helion Energy has taken the proven parts of fusion science and combined them into a design that can be commercially deployable within six years. That would be a decade ahead of Helion’s Bellevue neighbor, TerraPower LLC, a startup funded in part by Nathan Myhrvold and Bill Gates to build a traveling wave reactor that runs on uranium.


Helion Energy last week won the top prize in the Energy Generation category at the Cleantech Open Global Forum in Silicon Valley. The prize comes with a $5,000 check and a long menu of in-kind services. The audience also gave Helion a People’s Choice Award. The annual competition culminates a nine-month business accelerator for Cleantech startups.


The team at Helion comes out of the University of Washington and Mathematical Sciences Northwest. At its headquarters in Redmond, Helion has a working prototype that they say proves their design works. Deuterium gas goes in two ends of the device and produces a pair of plasmas per second. Plasma is responsible for the glow of lightning, neon lights and the Sun. As the two plasmas collide in the center, a magnetic pulse generates electricity.


At the Global Forum, Dr. Kirtley told me his design is compact, modular and competitive in today’s market. In the footprint of a semi trailer, each module will produce 50 megawatts of electricity (it would take ten of them to equal the output of a conventional power plant). The deuterium fuel is derived from seawater. The byproduct is a harmless stream of helium.


Helion Energy is raising $35 million to build a fusion reactor core that will demonstrate electricity production from fusion energy. Its technology previously received $4 million in funding from the U.S. Department of Energy.


“Helion isn’t looking for funding to do more science,” says Kirtley. “We already proved our technology. We’re now ready to start commercializing fusion energy.”

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Who's your daddy? Researchers program computer to find out

Who's your daddy? Researchers program computer to find out | Amazing Science | Scoop.it
A University of Central Florida research team has developed a facial recognition tool that promises to be useful in rapidly matching pictures of children with their biological parents and in potentially identifying photos of missing children as they age.


The work verifies that a computer is capable of matching pictures of parents and their children. The study will be presented at the nation's premier event for the science of computer vision - the IEEE Computer Vision and Pattern Recognition conference in Columbus, Ohio, which begins Monday, June 23. Graduate Student Afshin Dehfghan and a team from UCF's Center for Research in Computer Vision started the project with more than 10,000 online images of celebrities, politicians and their children.


"We wanted to see whether a machine could answer questions, such as 'Do children resemble their parents?' 'Do children resemble one parent more than another?' and 'What parts of the face are more genetically inspired?'" he said.


Anthropologists have typically studied these questions. However Dehghan and his team are advancing a new wave of computational science that uses the power of a mechanical "mind" to evaluate data completely objectively – without the clutter of subjective human emotions and biases. The tool could be useful to law enforcement and families in locating missing children.


"As this tool is developed I could see it being used to identify long-time missing children as they mature," said Ross Wolf, associate professor of criminal justice at UCF.


Wolf said that facial recognition technology is already heavily used by law enforcement, but that it has not been developed to the point where it can identify the same characteristics in photos over time, something this technology could have the capability to do. Dehghan said he is planning to expand on the work in that area by studying how factors such as age and ethnicity affect the resemblance of facial features.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Transplanting the TBX18 gene into injured hearts creates biological pacemakers

Transplanting the TBX18 gene into injured hearts creates biological pacemakers | Amazing Science | Scoop.it
Cardiologists have developed a minimally invasive gene transplant procedure that changes unspecialized heart cells into "biological pacemaker" cells that keep the heart steadily beating.


The laboratory animal research, published online and in today's print edition of the peer-reviewed journalScience Translational Medicine, is the result of a dozen years of research with the goal of developing biological treatments for patients with heart rhythm disorders who currently are treated with surgically implanted pacemakers. In the United States, an estimated 300,000 patients receive pacemakers every year.


"We have been able, for the first time, to create a biological pacemaker using minimally invasive methods and to show that the biological pacemaker supports the demands of daily life," said Eduardo Marbán, MD, PhD, director of the Cedars-Sinai Heart Institute, who led the research team. "We also are the first to reprogram a heart cell in a living animal in order to effectively cure a disease."


These laboratory findings could lead to clinical trials for humans who have heart rhythm disorders but who suffer side effects, such as infection of the leads that connect the device to the heart, from implanted mechanical pacemakers.


Eugenio Cingolani, MD, the director of the Heart Institute's Cardiogenetics-Familial Arrhythmia Clinic who worked with Marbán on biological pacemaker research team, said that in the future, pacemaker cells also could help infants born with congenital heart block.


"Babies still in the womb cannot have a pacemaker, but we hope to work with fetal medicine specialists to create a life-saving catheter-based treatment for infants diagnosed with congenital heart block," Cingolani said. "It is possible that one day, we might be able to save lives by replacing hardware with an injection of genes."


"This work by Dr. Marbán and his team heralds a new era of gene therapy, in which genes are used not only to correct a deficiency disorder, but to actually turn one kind of cell into another type," said Shlomo Melmed, dean of the Cedars-Sinai faculty and the Helene A. and Philip E. Hixson Distinguished Chair in Investigative Medicine.


In the study, laboratory pigs with complete heart block were injected with the gene called TBX18 during a minimally invasive catheter procedure. On the second day after the gene was delivered to the animals' hearts, pigs who received the gene had significantly faster heartbeats than pigs who did not receive the gene. The stronger heartbeat persisted for the duration of the 14-day study.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Researchers develop powerful single-cell epigenetic methylation mapping to study environmental effects on DNA

Researchers develop powerful single-cell epigenetic methylation mapping to study environmental effects on DNA | Amazing Science | Scoop.it

Researchers at the BBSRC-funded Babraham Institute, in collaboration with the Wellcome Trust Sanger Institute Single Cell Genomics Centre, have developed a powerful new single-cell technique to help investigate how the environment affects our development and the traits we inherit from our parents. The technique can be used to map all of the ‘epigenetic marks’ on the DNA within a single cell.  This single-cell approach will boost understanding of embryonic development, could enhance clinical applications like cancer therapy and fertility treatments, and has the potential to reduce the number of mice currently needed for this research.


‘Epigenetic marks’ are chemical tags or proteins that mark DNA and act as a kind of cellular memory. They do not change the DNA sequence but record a cell’s experiences onto the DNA, which allows cells to remember an experience long after it has faded. Placing these tags is part of normal development; they tell genes whether to be switched on or off and so can determine how the cell develops. Different sets of active genes make a skin cell different from a brain cell, for example. However, environmental cues such as diet can also alter where epigenetic tags are laid down on DNA and influence an organism’s long-term health.


Dr Gavin Kelsey, from the Babraham Institute, said: “The ability to capture the full map of these epigenetic marks from individual cells will be critical for a full understanding of early embryonic development, cancer progression and aid the development of stem cell therapies.


“Epigenetics research has mostly been reliant on using the mouse as a model organism to study early development. Our new single-cell method gives us an unprecedented ability to study epigenetic processes in human early embryonic development, which has been restricted by the very limited amount of tissue available for analysis.”


The new research, published in Nature Methods, offers a new single-cell technique capable of analysing DNA methylation – one of the key epigenetic marks – across the whole genome. The method treats the cellular DNA with a chemical called bisulphite. Treated DNA is then amplified and read on high-throughput sequencing machines to show up the location of methylation marks and the genes being affected.


These analyses will help to define how epigenetic changes in individual cells during early development drive cell fate. Current methods observe epigenetic marks in multiple, pooled cells. This can obscure modifications taking place in individual cells at a time in development when each cell has the potential to form in a unique way. The new method has already revealed that many of the methylation marks that differ between individual cells are precisely located in sites that control gene activity.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Proton Spin Mystery Gains a New Clue

Proton Spin Mystery Gains a New Clue | Amazing Science | Scoop.it

Physicists long assumed a proton’s spin came from its three constituent quarks. New measurements suggest particles called gluons make a significant contribution.


Protons have a constant spin that is an intrinsic particle property like mass or charge. Yet where this spin comes from is such a mystery it’s dubbed the “proton spin crisis.” Initially physicists thought a proton’s spin was the sum of the spins of its three constituent quarks. But a 1987 experiment showed that quarks can account for only a small portion of a proton’s spin, raising the question of where the rest arises. The quarks inside a proton are held together by gluons, so scientists suggested perhaps they contribute spin. That idea now has support from a pair of studies analyzing the results of proton collisions inside the Relativistic Heavy-Ion Collider (RHIC) at Brookhaven National Laboratory in Upton, N.Y.
 
Physicists often explain spin as a particle’s rotation, but that description is more metaphorical than literal. In fact, spin is a quantum quantity that cannot be described in classical terms. Just as a proton is not really a tiny marble but rather a jumble of phantom particles appearing and disappearing continuously, its spin is a complex probabilistic property. Yet it is always equal to one half.
 
Quarks also have a spin of one half. Physicists originally assumed that two of the proton’s three quarks were always spinning in opposite directions, canceling one another out, leaving the remaining one half as the proton’s total spin. “That was the naïve idea 25 years ago,” says Daniel de Florian of the University of Buenos Aires, leader of one of the new papers, which was published July 2, 2014 in Physical Review Letters. “By the end of the ‘80s it was possible to measure the contribution of the spin of the quarks to the spin of the proton, and the first measurement showed it was 0 percent. That was a very big surprise.” Later measurements actually suggested quarks can contribute up to 25 percent of the proton’s total spin, but that still leaves the lion’s share unaccounted for.
 
Gluons are also present inside protons as the representatives of the strong nuclear force, a fundamental interaction that binds the quarks together. Gluons each have a spin of 1, and depending on which direction it is they could add up to make most of rest of the proton’s spin. Measuring their contribution is a tricky task. RHIC is the only experiment that can address the question, because it is the only particle accelerator built to collide “spin-polarized” protons, meaning that the particles are all spinning in a certain direction when they crash. (At the more powerful Large Hadron Collider in Switzerland, the particles’ spins are not aligned.)
 
When two protons slam together, their interaction is controlled by the strong force, so gluons are intimately involved. If gluon spin is an important ingredient of proton spin, then the orientation of the colliding protons’ spins should affect the outcome. Scientists would expect collisions between two protons whose spins were aligned would happen at a different frequency than collisions between those spinning in opposite directions. And according to recent data from RHIC, there is a difference. “If there is no preferred position, the difference will be exactly zero,” says University of Oxford physicist Juan Rojo, a member of the so-called NNPDF Collaboration that wrote the second paper, which was submitted to Nuclear Physics B.


“Since the asymmetry is not zero, this tells us the distribution of the spin is not trivial.” Rojo’s team calculated that gluons probably contribute about half the spin that quarks do to the proton. De Florian and his colleagues analyzed the same data from RHIC, but used a different mathematical analysis to calculate the gluon contribution. They also found that gluon spin must be significantly involved. “This data for the first time shows the gluon polarization is actually nonzero; we see the gluons are polarized,” de Florian says. “Basically they could be responsible for the rest of the proton spin, but the uncertainty is very large.”

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Fecal Transplants of Bacteria Let Packrats Eat Poisonous Creosote Diet

Fecal Transplants of Bacteria Let Packrats Eat Poisonous Creosote Diet | Amazing Science | Scoop.it

Woodrats lost their ability to eat toxic creosote bushes after antibiotics killed their gut microbes. Woodrats that never ate the plants were able to do so after receiving fecal transplants with microbes from creosote-eaters, University of Utah biologists found.


The new study confirms what biologists long have suspected: bacteria in the gut – and not just liver enzymes – are “crucial in allowing herbivores to feed on toxic plants,” says biologist Kevin Kohl, a postdoctoral researcher and first author of the paper published online today in the journal Ecology Letters.


Many plants produce toxic chemicals, which they use as a defense against herbivores, or plant-eating animals. A toxic resin coats the leaves of the creosote bush; juniper toxins are found inside juniper needles.

Most mammals are herbivores. Some face serious challenges: their bodies must handle up to hundreds of toxic chemicals from the plants they consume each day. “Plant toxins determine which plants a herbivore can eat,” says Kohl.


Liver enzymes help animals detoxify such poisons. Researchers previously isolated toxin-degrading microbes from herbivores, but Kohl and Dearing say that, until now, scientists have lacked strong evidence for what has been conventional wisdom: Gut microbes also help some herbivores eat toxic plants.


more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Barnacle cement: Nature's strongest glue is a two-component adhesive

Barnacle cement: Nature's strongest glue is a two-component adhesive | Amazing Science | Scoop.it

Over a 150 years since it was first described by Darwin, scientists are finally uncovering the secrets behind the super strength of barnacle glue. 

Still far better than anything we have been able to develop synthetically, barnacle glue – or cement - sticks to any surface, under any conditions.

But exactly how this superglue of superglues works has remained a mystery – until now.


An international team of scientists led by Newcastle University, UK, and funded by the US Office of Naval Research, have shown for the first time that barnacle larvae release an oily droplet to clear the water from surfaces before sticking down using a phosphoprotein adhesive.


Publishing their findings this week in the prestigious academic journal Nature Communications, author Dr Nick Aldred says the findings could pave the way for the development of novel synthetic bioadhesives for use in medical implants and micro-electronics. The research will also be important in the production of new anti-fouling coatings for ships.


Thoracian barnacles rely heavily upon their ability to adhere to surfaces and are environmentally and economically important as biofouling pests. Their adhesives have unique attributes that define them as targets for bio-inspired adhesive development. With the aid of multi-photon and broadband coherent anti-Stokes Raman scattering microscopies, we report that the larval adhesive of barnacle cyprids is a bi-phasic system containing lipids and phosphoproteins, working synergistically to maximize adhesion to diverse surfaces under hostile conditions. Lipids, secreted first, possibly displace water from the surface interface creating a conducive environment for introduction of phosphoproteins while simultaneously modulating the spreading of the protein phase and protecting the nascent adhesive plaque from bacterial biodegradation. The two distinct phases are contained within two different granules in the cyprid cement glands, implying far greater complexity than previously recognized. Knowledge of the lipidic contribution will hopefully inspire development of novel synthetic bioadhesives and environmentally benign antifouling coatings.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Speedy computation enables scientists to reconstruct an animal's development cell by cell

Speedy computation enables scientists to reconstruct an animal's development cell by cell | Amazing Science | Scoop.it
Researchers have developed a new computational method that can rapidly track the three-dimensional movements of cells in such data-rich images. Using the method, scientists can essentially automate much of the time-consuming process of reconstructing an animal's developmental building plan cell by cell.


Recent advances in imaging technology are transforming how scientists see the cellular universe, showing the form and movement of once grainy and blurred structures in stunning detail. But extracting the torrent of information contained in those images often surpasses the limits of existing computational and data analysis techniques, leaving scientists less than satisfied.


Now, researchers at the Howard Hughes Medical Institute's Janelia Research Campus have developed a way around that problem. They have developed a new computational method that can rapidly track the three-dimensional movements of cells in such data-rich images. Using the method, the Janelia scientists can essentially automate much of the time-consuming process of reconstructing an animal's developmental building plan cell by cell.


Philipp Keller, a group leader at Janelia, led the team that developed the computational framework. He and his colleagues, including Janelia postdoc Fernando Amat, Janelia group leader Kristin Branson and former Janelia lab head Eugene Myers, who is now at the Max Plank Institute of Molecular Cell Biology and Genetics, have used the methodto reconstruct cell lineage during development of the early nervous system in a fruit fly. Their method can be used to trace cell lineages in multiple organisms and efficiently processes data from multiple kinds of fluorescent microscopes.


The scientists describe their approach in a paper published online on July 20, 2014, in Nature Methods.


"With this fairly fast, simple approach, we can solve easy cases fairly efficiently," Keller says. Those cases make up about 95 percent of the data. "In harder cases, where we might have mistakes, we use heavier machinery."


He explains that in instances where cells are harder to track -- because image quality is poor or cells are crowded, for example -- the computer draws on additional information. "We look at what all the cells in that neighborhood do a little bit into the future and a little bit into the past," Keller explains. Informative patterns usually emerge from that contextual information. The strategy takes more computing power than the initial tactics. "We don't want to do it for all the cells," Keller says. "But we try to crack these hard cases by gathering more information and making better informed decisions."


All of these steps can be carried out as quickly as images are acquired by the microscope, and the result is lineage information for every cell. "You know the path, you know where it is at a certain time point. You know it divided at a certain point, you know the daughter cells, you know what mother cell it came from," Keller says.


New York TImes article


more...
No comment yet.