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Therapeutic siRNA Interventions: What we have learned

Therapeutic siRNA Interventions: What we have learned | Amazing Science | Scoop.it

Treatments based on RNA interference are improving now that technologies are delivering longer-lasting gene silencing.


The 2006 Nobel Prize in Physiology or Medicine was awarded jointly to Andrew Z. Fire and Craig C. Mello for their 1998 discovery of RNA interference (RNAi), gene silencing by double-stranded RNA.

Today, RNAi-based therapeutics are in Phase II and Phase III clinical trials. The rapid development of this technology demonstrates its enormous potential for treatment of a range of diseases.

A major hurdle for clinical applications is the safe and effective delivery of small interfering RNA (siRNA). Unlike biologics that target membrane proteins, siRNA molecules need to enter the cytosol of diseased cells to work. In addition, unlike small molecules that diffuse freely across the cell membrane, siRNA molecules are large and negatively charged. They cannot easily and independently cross the cell membrane.

Current siRNA nanoparticle delivery platforms in clinical trials, such as cationic lipoplexes and polyplexes, induce transient gene silencing; they lack a sustained siRNA release property. In vitro studies have indicated that efficacy, in general, lasts less than two weeks at the cellular level.

A new lipid-polymer hybrid nanoparticle combines a cationic liposome system with a controlled-release polymer technology, allowing siRNA encapsulation along with sustained release. Encapsulation of the siRNA would be very low if it depended solely on the noncharged, controlled-release polymer technology. Sustained delivery allows for longer activity, and, potentially, subsequent lower dosage and injection frequencies.

An in vitro proof-of-concept study showed that the lipid-polymer hybrid nanoparticle slowly releases the siRNA over the course of a month, allowing sustained knockdown of PHB1, a protein involved in cell proliferation, apoptosis, chemoresistance, and other biological processes in lung carcinoma cells.

“It takes a long time to discover a drug or small molecule to target a protein of interest, plus there are many undruggable proteins. The beautiful thing about RNAi technology is you can target any protein you want by silencing the gene,” explains Jinjun Shi, Ph.D., assistant professor, Laboratory for Nanoengineering and Drug Delivery, Department of Anesthesiology, Brigham and Women’s Hospital, Harvard Medical School.

The new lipid-polymer hybrid nanoparticle technology is initially intended for use in fundamental research and target validation. The goal is to eventually extend its application to the clinic as a vehicle for delivering therapeutic siRNAs and, perhaps, for co-delivering chemotherapeutics and siRNAs for synergistic cancer treatment.


Via Integrated DNA Technologies
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Seeing around corners: When light echoes, the invisible becomes visible

Seeing around corners: When light echoes, the invisible becomes visible | Amazing Science | Scoop.it

How to see around a corner without a mirror | KurzweilAIScientists at the University of Bonn and the University of British Columbia (Vancouver, Canada) have developed a novel camera system which can see around the corner without using a mirror. Using diffusely reflected light, it reconstructs the shape of objects outside of the field of view. The researchers will be reporting their results at the international Conference for Computer Vision and Pattern Recognition (CVPR) from June 24-27 in Columbus (Ohio, USA).


A laser shines on the wall; a camera watches the scene. Nothing more than white ingrain wallpaper with a bright spot of light can be seen through the lens. A computer records these initially unremarkable images and as the data is processed further, little by little, the outlines of an object appear on a screen. Yet, this object is behind a partition and the camera cannot possibly have seen it – we have apparently looked around the corner. A magic trick? "No," says Prof. Dr.-Ing. Matthias B. Hullin from the Institute of Computer Science II at the University of Bonn. "This is an actual reconstruction from diffusely scattered light. Our camera, combined with a mathematical procedure, enables us to virtually transform this wall into a mirror." Scattered light is used as a source of information.


The laser dot on the wall is by itself a source of scattered light, which serves as the crucial source of information. Some of this light, in a roundabout way, falls back onto the wall and finally into the camera. "We are recording a kind of light echo, that is, time-resolved data, from which we can reconstruct the object," explains the Bonn computer scientist. "Part of the light has also come into contact with the unknown object and it thus brings valuable information with it about its shape and appearance." To be able to measure such echoes, a special camera system is required which Prof. Hullin has developed together with his colleagues at the University of British Columbia (Vancouver, Canada) and further refined after his return to Bonn. In contrast to conventional cameras, it records not just the direction from which the light is coming but also how long it took the light to get from the source to the camera.


The technical complexity for this is comparatively low – suitable image sensors came onto the mass market long ago. They are mainly found in depth image cameras as they are used, for instance, as video game controllers or for range measurements in the automotive field. The actual challenge is to elicit the desired information from such time-of-flight measurements. Hullin compares the situation to a room which reverberates so greatly that one can no longer have a conversation with one's partner. "In principle, we are measuring nothing other than the sum of numerous light reflections which reached the camera through many different paths and which are superimposed on each other on the image sensor."


This problem, known as multipath interference, has been giving engineers headaches for a long time. Traditionally, one would attempt to remove the undesired multipath scatter and only use the direct portion of the signal. Based on an advanced mathematical model, Hullin and his colleagues, however, developed a method which can obtain the desired information exclusively from what would usually be considered noise rather than signal. Since multipath light also originates from objects which are not at all in the field of view, the researchers can thus make visible what is virtually invisible.


Minimal technical complexity and intelligent programming

"The accuracy of our method has its limits, of course," says Prof. Hullin – the results are still limited to rough outlines. However, the researchers assume that based on the rapid development of technical components and mathematical models, an even higher resolution can be achieved soon. Together with his colleagues, he will present the method at the international Conference for Computer Vision and Pattern Recognition (CVPR) from June 24 to 27 in Columbus (Ohio, USA). The new technology is received with great interest – Hullin hopes that similar approaches can be used, for example, in telecommunications, remote sensing and medical imaging.

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The Shadow Internet That’s 100 Times Faster Than Even Google Fiber

The Shadow Internet That’s 100 Times Faster Than Even Google Fiber | Amazing Science | Scoop.it

When Google chief financial officer Patrick Pichette said the tech giant might bring 10 gigabits per second internet connections to American homes, it seemed like science fiction. That’s about 1,000 times faster than today’s home connections. But for NASA, it’s downright slow.


While the rest of us send data across the public internet, the space agency uses a shadow network called ESnet, short for Energy Science Network, a set of private pipes that has demonstrated cross-country data transfers of 91 gigabits per second–the fastest of its type ever reported.


NASA isn’t going bring these speeds to homes, but it is using this super-fast networking technology to explore the next wave of computing applications. ESnet, which is run by the U.S. Department of Energy, is an important tool for researchers who deal in massive amounts of data generated by projects such as the Large Hadron Collider and the Human Genome Project. Rather sending hard disks back and forth through the mail, they can trade data via the ultra-fast network. “Our vision for the world is that scientific discovery shouldn’t be constrained by geography,” says ESnet director Gregory Bell.


In making its network as fast as it can possibly be, ESnet and researchers are organizations like NASA are field testing networking technologies that may eventually find their way into the commercial internet. In short, ESnet a window into what our computing world will eventually look like.


ESnet has long been capable of 100 gigabit transfers, at least in theory. Network equipment companies have been offering 100 gigabit switches since 2010. But in practice, long-distance transfers were much slower. That’s because data doesn’t travel through the internet in a straight line. It’s less like a super highway and more like an interstate highway system. If you wanted to drive from San Francisco to New York, you’d pass through multiple cities along the way as you transferred between different stretches of highway. Likewise, to send a file from San Francisco to New York on the internet—or over ESnet—the data will flow through hardware housed in cities across the country.


NASA did a 98 gigabit transfer between Goddard and the University of Utah over ESnet in 2012. And Alcatel-Lucent and BT obliterated that record earlier this year with a 1.4 terabit connection between London and Ipswich. But in both cases, the two locations had a direct connection, something you rarely see in real world connections.


On the internet and ESnet, every stop along the way creates the potential for a bottleneck, and every piece of gear must be ready to handle full 100 gigabit speeds. In November, the team finally made it work. “This demonstration was about using commercial, off-the-shelf technology and being able to sustain the transfer of a large data network,” says Tony Celeste, a sales director at Brocade, the company that manufactured the equipment used in the record-breaking test.

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Ellie Kesselman Wells's comment, July 22, 2014 9:20 AM
I don't suppose this is the follow-up to Internet 2?
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A super-stretchable yarn made of graphene

A super-stretchable yarn made of graphene | Amazing Science | Scoop.it

A simple, scalable method of making strong, stretchable graphene oxide fibers that are easily scrolled into yarns and have strengths approaching that of Kevlar is possible, according to Penn State and Shinshu University, Japan, researchers.


“We found this graphene oxide fiber was very strong, much better than other carbon fibers,” said Mauricio Terrones, professor of physics, chemistry and materials science and engineering, Penn State. “We believe that pockets of air inside the fiber keep it from being brittle.”


This method opens up multiple possibilities for useful products, according to Terrones and colleagues. For instance, removing oxygen from the graphene oxide fiber results in a fiber with high electrical conductivity.


Adding silver nanorods to the graphene film would increase the conductivity to the same as copper, which could make it a much lighter weight replacement for copper transmission lines. The researchers believe that the material lends itself to many kinds of highly sensitive sensors.


The researchers made a thin film of graphene oxide by chemically exfoliating graphite into graphene flakes, which were then mixed with water and concentrated by centrifugation into a thick slurry. The slurry was then spread by bar coating — something like a squeegee — across a large plate. When the slurry dries, it becomes a large-area transparent film that can be carefully lifted off without tearing. The film is then cut into narrow strips and wound on itself with an automatic fiber scroller, resulting in a fiber that can be knotted and stretched without fracturing. The researchers reported their results in a recent issue of ACSNano.


“The importance is that we can do almost any material, and that could open up many avenues — it’s a lightweight material with multifunctional properties,” said Terrones. And the main ingredient, graphite, is mined and sold by the ton.”

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Reconstruction of 1918-like avian influenza virus stirs concern over gain of function experiments

Reconstruction of 1918-like avian influenza virus stirs concern over gain of function experiments | Amazing Science | Scoop.it

The gain of function experiments in which avian influenza H5N1 virus was provided the ability to transmit by aerosol among ferrets were met with substantial outrage from both the press and even some scientists; scenarios of lethal viruses escaping from the laboratory and killing millions proliferated (see examples here and here). The recent publication of new influenza virus gain of function studies from the laboratories of Kawaoka and Perez have unleashed another barrage of criticism.


The work by Kawaoka and colleagues attempts to answer the question of whether an influenza virus similar to that which killed 50 million people in 1918 could emerge today. First they identified in the avian influenza virus sequence database individual RNA segments that encode proteins that are very similar to the 1918 viral proteins.


Next, an infectious influenza virus was produced with 8 RNA segments that encode proteins highly related to those of the 1918 virus. Each RNA segment originates from a different avian influenza virus, and differs by 8 (PB2), 6 (PB1), 20 (PB1-F2), 9 (PA), 7 (NP), 33 (HA), 31 (NA), 1 (M1), 5 (M2), 4 (NS1), and 0 (NS2) amino acids from the 1918 virus.


The 1918-like avian influenza virus was less pathogenic in mice and ferrets compared with the 1918 virus, and more pathogenic than a duck influenza virus isolated in 1976. Virulence in ferrets increased when the HA or PB2 genes of the 1918-like avian influenza virus were substituted with those from the 1918 virus.


Aerosol transmission among ferrets was determined for the 1918-like avian influenza virus, and reassortants containing 1918 viral genes (these experiments are done by housing infected and uninfected ferrets in neighboring cages). The 1918 influenza virus was transmitted to 2 of 3 ferrets. Neither the 1918-like avian influenza virus, nor the 1976 duck influenza virus transmitted among ferrets. Aerosol transmission among ferrets was observed after infection with two different reassortant viruses of the 1918-avian like influenza virus: one which possesses the 1918 virus PB2, HA, and NA RNAs (1918 PB2:HA:NA/Avian), and one which possesses the 1918 virus PA, PB1, PB2, NP, and HA genes (1918(3P+NP):HA/Avian).


It is known from previous work that amino acid changes in the viral HA and PB2 proteins are important in allowing avian influenza viruses to infect humans. Changes in the viral HA glycoprotein (HA190D/225D) shift receptor specificity from avian to human sialic acids, while a change at amino acid 627 of the PB2 protein to a lysine (627K) allows avian influenza viruses to efficiently replicate in mammalian cells, and at the lower temperatures of the human upper respiratory tract.


These changes were introduced into the genome of the 1918-like avian influenza virus. One of three contact ferrets was infected with 1918-like avian PB2-627K:HA-89ED/190D/225D virus (a mixture of glutamic acid and aspartic acid at amino acid 89 was introduced during propagation of the virus in cell culture). Virus recovered from this animal had three additional mutations: its genotype is 1918-like avian PB2-627K/684D : HA-89ED/113SN/ 190D/225D/265DV : PA-253M (there are mixtures of amino acids at HA89, 113, and 265). This virus was more virulent in ferrets and transmitted by aerosol more efficiently than the 1918-like avian influenza virus. The virus recovered from contact ferrets contained yet another amino acid change, a T-to-I mutation at position 232 of NP. Therefore ten amino acid changes are associated with allowing the 1918-like avian influenza virus to transmit by aerosol among ferrets. Aerosol transmission of these viruses is not associated with lethal disease in ferrets.


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Computer spots rare diseases in family photos

Computer spots rare diseases in family photos | Amazing Science | Scoop.it

Could software reveal whether Abraham Lincoln had Marfan syndrome? Doctors faced with the tricky task of spotting rare genetic diseases in children may soon be asking parents to email their family photos. A computer program can now learn to identify rare conditions by analysing a face from an ordinary digital photograph. It should even be able to identify unknown genetic disorders if groups of photos in its database share specific facial features.


Rare genetic disorders are thought to affect 6 per cent of people. Genetic tests exist for the more common conditions such as Down's syndrome, but many people with the rarer disorders never get a proper clinical diagnosis. Genetic tests aren't available for many conditions because the gene variants that cause them haven't been identified. This means doctors often have to rely on the pronounced facial features that occur in between 30 and 40 per cent of rare disorders to make a diagnosis, but few people are trained to recognise them.


"Clinicians skilled in the use of facial features to support diagnosis are few and far between," says Alastair Kent, director of the charity Genetic Alliance UK. "As a result, families frequently experience long delays – years rather than months – before they receive a diagnosis for their child."


The software developed by Christoffer Nellåker and Andrew Zisserman of the University of Oxford and their colleagues should help family doctors or general paediatricians make a preliminary diagnosis. "The idea is to offer it to health systems right across the world because all you need is a computer and a digital photo," says Nellåker.


To train the system, Nellåker's team fed a computer vision algorithm 1363 publicly available pictures of people with eight genetic disorders, including Down's syndrome, fragile X syndrome and progeria (fourth, fifth and sixth in the graphic below). The computer learned to identify each condition from a pattern of 36 facial features in each shot, such as the shapes of eyes, brows, lips and noses.


"It automatically analyses the picture and annotates key feature points, producing from that a description of the face which expands the features that are important for distinctiveness," Nellåker says. These features are then compared with those from pictures of patients with confirmed disorders, allowing the system to suggest and rank predictions for new patients.


To show that it works, the team analysed photos of people with known genetic disorders. The accuracy of the software increases with the number of photos of a specific disorder it learns from. For the eight training diseases, for example, each disorder was represented by between 100 and 283 images. On average, this resulted in 93 per cent of the predictions being correct.

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Not as random as thought: Modeling how neurons work together to perform complex movements

Not as random as thought: Modeling how neurons work together to perform complex movements | Amazing Science | Scoop.it

In a bid to better understand the brain and also to create robotics limbs that behave more realistically, a team of three European universities has developed a highly accurate new model of how neurons behave when performing complex movements.


The results from the University of CambridgeUniversity of Oxford, and the Ecole Polytechnique Fédérale de Lausanne (EPFL) are published in the June 18 edition of the journal Neuron.


The new theory was inspired by recent experiments carried out at Stanford University, which had uncovered some key aspects of the signals that neurons emit before, during, and after a movement. “There is a remarkable synergy in the activity recorded simultaneously in hundreds of neurons,” said Guillaume Hennequin, PhD, of EPFL’s Department of Engineering, who led the research. “In contrast, previous models of cortical circuit dynamics predict a lot of redundancy, and therefore poorly explain what happens in the motor cortex during movements.”


I addition to helping us better understand the brain, better models of how neurons behave will aid in designing prosthetic limbs controlled via electrodes implanted in the brain. “Our theory could provide a more accurate guess of how neurons would want to signal both movement intention and execution to the robotic limb,” said Hennequin.


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Diet restriction suspends development in nematode worms and doubles lifespan

Diet restriction suspends development in nematode worms and doubles lifespan | Amazing Science | Scoop.it

Researchers at Duke University have found that taking food away from the C. elegans nematode worm triggers a state of arrested development: while the organism continues to wriggle about, foraging for food, its cells and organs are suspended in an ageless, quiescent state. When food becomes plentiful again, the worm develops as planned, but can live twice as long as normal.


The study found that C. elegans could be starved for at least two weeks and still develop normally once feeding resumed. Because the meter isn’t running while the worm is in its arrested state, this starvation essentially doubles the two-week lifespan of the worm. “It is possible that low-nutrient diets set off the same pathways in us to put our cells in a quiescent state,” said David R. Sherwood, an associate professor of biology at Duke University. “The trick is to find a way to pharmacologically manipulate this process so that we can get the anti-aging benefits without the pain of diet restriction.”


Over the last 80 years, researchers have put a menagerie of model organisms on a diet, and they’ve seen that nutrient deprivation can extend the lifespan of rats, mice, yeast, flies, spiders, fish, monkeys and worms anywhere from 30 percent to 200 percent longer than their free-fed counterparts.


Outside the laboratory and in the real world, organisms like C. elegans can experience bouts of feast or famine that no doubt affect their development and longevity. Sherwood’s colleague Ryan Baugh, an assistant professor of medicine at Duke, showed that hatching C. elegans eggs in a nutrient-free environment shut down their development completely. He asked Sherwood to investigate whether restricting diet to the point of starvation later in life would have the same effect.


Sherwood and his postdoctoral fellow Adam Schindler decided to focus on the last two stages of C. elegans larval development — known as L3 and L4 — when critical tissues and organs like the vulva are still developing. During these stages, the worm vulva develops from a speck of three cells to a slightly larger ball of 22 cells. The researchers found that when they took away food at various times throughout L3 and L4, development paused when the vulva was either at the three-cell stage or the 22-cell stage, but not in between.


When they investigated further, the researchers found that not just the vulva, but all the tissues and cells in the organism seemed to get stuck at two main checkpoints. These checkpoints are like toll booths along the developmental interstate. If the organism has enough nutrients, its development can pass through to the next toll booth. If it doesn’t have enough, it stays at the toll booth until it has built up the nutrients necessary to get it the rest of the way.


“Development isn’t a continuous nonstop process,” said Schindler, who is lead author of the study. “Organisms have to monitor their environment and decide whether or not it is amenable to their development. If it isn’t, they stop, if it is, they go. Those checkpoints seem to exist to allow the animal to make that decision. And the decision has implications, because the resources either go to development or to survival.”

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If the World Began Again, Would Life as We Know It Exist?

If the World Began Again, Would Life as We Know It Exist? | Amazing Science | Scoop.it

The Long-Term Evolution Experiment, as the E. coli project is known, has surpassed 60,000 generations now, giving Lenski a deep data set from which to draw inferences about the interplay of contingency and convergence in evolution. Subtle changes in the bacteria’s DNA that make them larger and better able to proliferate in the flask have been relatively common across the groups. At the same time, Lenski has witnessed “striking” cases of contingency, in which one population did something completely different than the others. But as in convergence, he adds, these transformations weren’t entirely random.

 

http://nautil.us/issue/14/mutation/if-the-world-began-again-would-life-as-we-know-it-exist


Via Complexity Digest, Ashish Umre
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Sad statistics: 25 Alarming Global Warming Facts

Sad statistics: 25 Alarming Global Warming Facts | Amazing Science | Scoop.it

Global warming is among the most alarming environmental issues that the world faces today. This phenomenon does not simply involve the significant rise in the earth’s temperature but a lot more. The adverse effects of global warming have become more and more apparent since the dawn of the 20th century, with more hurricanes and tropical storms causing massive destruction in different areas around the world, more animal species losing their habitats and becoming extinct, and more people dying because of too much heat. Here are 25 alarming global warming statistics.

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Marc Kneepkens's curator insight, June 20, 2014 8:12 PM

Alarming numbers.

Jim Doyle's curator insight, June 23, 2014 8:51 AM

Sad statistics: 25 Alarming Global Warming Facts

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2014 Cancer Survivorship Statistics – 10 Key Facts

2014 Cancer Survivorship Statistics – 10 Key Facts | Amazing Science | Scoop.it

The number of Americans with a history of cancer is growing due to the aging and growth of the population, as well as improving survival rates. Nearly 14.5 million Americans with a history of cancer were alive on January 1, 2014, not including carcinoma in situ (non-invasive cancer) of any site except urinary bladder, and not including basal cell and squamous cell skin cancers. It is estimated that by January 1, 2024, the population of cancer survivors will increase to almost 19 million: 9.3 million males and 9.6 million females.


The three most common cancers among male survivors are prostate (43%), colon and rectum (9%), and melanoma (8%). Among female survivors, the most common cancers are breast (41%), uterine corpus (8%), and colon and rectum (8%).


The majority of cancer survivors (64%) were diagnosed 5 or more years ago, and 15% were diagnosed 20 or more years ago. Almost half (45%) of cancer survivors are 70 years of age or older, while only 5% are younger than 40 years.


This newest title in the American Cancer Society’s Cancer Facts and Figures series, a collaboration with the National Cancer Institute, provides current and projected cancer prevalence estimates for the United States, as well as data from the National Cancer Data Base on treatment patterns, and information on the common effects of cancer and its treatment. This publication contains information about treatment, survival, and other related concerns for the most common cancer types, as well as information on the side effects of cancer treatment.


Picture link: Cancer Statistics Map (click to magnify)

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Crossing the Interspecies Barrier: Opening the Door to Zoonotic Pathogens

Crossing the Interspecies Barrier: Opening the Door to Zoonotic Pathogens | Amazing Science | Scoop.it

The number of pathogens known to infect humans is ever increasing. Whether such increase reflects improved surveillance and detection or actual emergence of novel pathogens is unclear. Nonetheless, infectious diseases are the second leading cause of human mortality and disability-adjusted life years lost worldwide [1-2]. On average, three to four new pathogen species are detected in the human population every year [3]. Most of these emerging pathogens originate from nonhuman animal species.


Zoonotic pathogens represent approximately 60% of all known pathogens able to infect humans [4]. Their occurrence in humans relies on the human-animal interface, defined as the continuum of contacts between humans and animals, their environments, or their products. The human-animal interface has existed since the first footsteps of the human species and its hominin ancestors 6–7 million years ago, promoting the prehistoric emergence of now well-established human pathogens [5]. These presumably include pathogens with roles in the origin of chronic diseases, such as human T-lymphotropic viruses and Helicobacter pylori, as well as pathogens causing major crowd diseases, such as the smallpox and measles viruses and Bordetella pertussis [6]. Since prehistory, the human-animal interface has continued to evolve and expand, ever allowing new pathogens to access the human host and cross species barriers [5].


Species Barriers:

The suitability of any species to act as a host to a particular pathogen varies due to both host species– and pathogen-dependent factors, which define the species barriers. The species barriers separating nonhuman animal species from humans and thus of concern for zoonotic pathogens are the focus of this paper. However, the proposed conceptual framework is applicable to any host-pathogen system.


The species barriers separating nonhuman animal species from humans represent a major hurdle for effective exposure to, infection by, and subsequent spread of zoonotic pathogens among humans [7]. Accordingly, these species barriers can be divided into three largely complementary sets. First, the interspecies barrier determines the nature and level of human exposure to zoonotic pathogens. Second, the intrahuman barrier determines the ability of zoonotic pathogens to productively infect a human host and effectively cope with the immune response. Third, the interhuman barrier determines the ability of zoonotic pathogens to efficiently transmit among humans, causing outbreaks, epidemics, or pandemics. Zoonotic pathogens may cross, more or less efficiently, one or more of these sets of barriers. Only pathogens that cross all barriers have the potential to sustainably establish in the human population.


Via Mel Melendrez-Vallard
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Bionic Human: The latest of realistic, artificial body parts

Bionic Human: The latest of realistic, artificial body parts | Amazing Science | Scoop.it

From lab-grown lungs to mechanical eyes, the latest, and most realistic, artificial body parts.

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Hubble captures incredible star explosion in four-year time-lapse video

Hubble captures incredible star explosion in four-year time-lapse video | Amazing Science | Scoop.it

The unusual variable star V838 Monocerotis (V838 Mon) continues to puzzle astronomers. This previously inconspicuous star underwent an outburst early in 2002, during which it temporarily increased in brightness to become 600,000 times more luminous than our Sun. Light from this sudden eruption is illuminating the interstellar dust surrounding the star, producing the most spectacular "light echo" in the history of astronomy.

As light from the eruption propagates outward into the dust, it is scattered by the dust and travels to the Earth. The scattered light has travelled an extra distance in comparison to light that reaches Earth directly from the stellar outburst. Such a light echo is the optical analogue of the sound echo produced when an Alpine yodel is reflected from the surrounding mountainsides.

The NASA/ESA Hubble Space Telescope has been observing the V838 Mon light echo since 2002. Each new observation of the light echo reveals a new and unique "thin-section" through the interstellar dust around the star. This video morphs images of the light echo from the Hubble taken at multiple times between 2002 and 2006. The numerous whorls and eddies in the interstellar dust are particularly noticeable. Possibly they have been produced by the effects of magnetic fields in the space between the stars.


VIDEO

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Monarch butterflies employ a light-dependent magnetic compass during migration

Monarch butterflies employ a light-dependent magnetic compass during migration | Amazing Science | Scoop.it
Scientists have identified a new component of the complex navigational system that allows monarch butterflies to transverse the 2,000 miles to their overwintering habitat each year. Monarchs use a light-dependent, inclination magnetic compass to help them orient southward during migration.


Previous attempts by scientists to isolate use of an internal inclination compass in monarchs have yielded conflicting or unconvincing results. These studies, however, may not have accounted for the possibility that the magnetic compass was influenced by ultraviolet light that can penetrate cloud cover.


Given the ability of monarch cryptochromes (CRY), a class of proteins that are sensitive to ultraviolet A/blue light, to restore a light-dependent magnetic response in CRY-deficient Drosophila, Reppert and colleagues suspected that monarchs also possessed a light-dependent magnetic compass.


Using flight simulators equipped with artificial magnetic fields, Patrick Guerra, PhD, a postdoctoral fellow in the Reppert lab, examined monarch flight behavior under diffuse white light conditions. He found that tethered monarchs in the simulators oriented themselves in a southerly direction. Further tests in the simulator revealed that the butterflies used the inclination angle of Earth's magnetic field to guide their movement. Reversing the direction of the inclination caused the monarchs to orient in the opposite direction, to the north instead of the south.


To test the light-dependence of the monarch's magnetic compass, Dr. Guerra applied a series of wavelength blocking filters to the lights in the simulator. Monarchs exposed to light only in the wavelength range above 420nm exhibited a lack of direction by flying in circles. Monarchs exposed to light in the wavelength range above 380nm showed clear signs of directional flight. These tests showed that the monarch's magnetic compass, and thus directional flight, was dependent on exposure to light wavelengths (380nm to 420nm) found in the ultraviolet A/blue light spectral range.


Together, these results provide the first demonstration that the monarch butterfly uses a light-dependent, inclination compass during its long journey. It is also the first evidence of such a navigational tool in a long-distance migratory insect.


  1. Patrick A Guerra, Robert J Gegear, Steven M Reppert. A magnetic compass aids monarch butterfly migrationNature Communications, 2014; 5 DOI:10.1038/ncomms5164
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World's First Magnetic Hose Created

World's First Magnetic Hose Created | Amazing Science | Scoop.it

An international team of scientists led by researchers from the Department of Physics of the Universitat Autònoma de Barcelona has developed a material which guides and transports a magnetic field from one location to the other, similar to how an optical fibre transports light or a hose transports water.


The magnetic hose designed by the researchers consists of a ferromagnetic cylinder covered by a superconductor material, a surprisingly simple design given the complicated theoretical calculations and numerous lab tests it had to undergo. A 14-centimeter prototype was built, which transports the magnetic field from one extreme to the other with a efficiency of 400% in comparison to current methods used to transport these fields.
 
Even with the efficiency of the prototype, researchers theoretically demonstrated that the magnetic hose can be even more efficient if the ferromagnetic tube is covered with  thin layers of alternating superconductor and ferromagnetic material.
 
The device designed by the researchers can be implemented at any scale, even at nanometre scale. Thus, a magnetic nanohose capable of individually controlling quantum systems could help to solve some of the current technological problems existing in quantum computing.


Reference paper:
C. Navau, J. Prat-Camps, O. Romero-Isart, J. I. Cirac, and A. Sanchez. “Long-distance transfer and routing of static magnetic fields”. Phys. Rev. Lett. 112, 253901 (2014).

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Acid oceans threaten creatures that supply half the world's oxygen

Acid oceans threaten creatures that supply half the world's oxygen | Amazing Science | Scoop.it
Ocean acidification is turning phytoplankton toxic. Bad news for the many species - us, included - that rely on them as a principal source of food and oxygen.


What happens when phytoplankton, the (mostly) single-celled organisms that constitute the very foundation of the marine food web, turn toxic? Their toxins often concentrate in the shellfish and many other marine species (from zooplankton to baleen whales) that feed on phytoplankton. Recent trailblazing research by a team of scientists aboard the RV Melville shows that ocean acidification will dangerously alter these microscopic plants, which nourish a menagerie of sea creatures and produce up to 60 percent of the earth's oxygen.


The researchers worked in carbon saturated waters off the West Coast, a living laboratory to study the effects of chemical changes in the ocean brought on by increased atmospheric carbon dioxide. A team of scientists from NOAA's Fisheries Science Center and Pacific Marine Environmental Lab, along with teams from universities in Maine, Hawaii and Canada focused on the unique "upwelled" zones of California, Oregon and Washington. In these zones, strong winds encourage mixing, which pushes deep, centuries-old CO2 to the ocean surface. Their findings could reveal what oceans of the future will look like. The picture is not rosy.


Scientists already know that ocean acidification, the term used to describe seas soured by high concentrations of carbon, causes problems for organisms that make shells. “What we don't know is the exact effects ocean acidification will have on marine phytoplankton communities,” says Dr. Bill Cochlan, the biological oceanographer from San Francisco State University oceanographer who was the project’s lead investigator. “Our hypothesis is that ocean acidification will affect the quantity and quality of certain metabolities within the phytoplankton, specifically lipids and essential fatty acids.”

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Scott Baker's curator insight, June 25, 2014 10:00 AM

will fertilization help?  http://nextbigfuture.com/2014/06/russ-george-blogged-about-fraser-river.html

Diane Johnson's curator insight, June 25, 2014 12:12 PM

Understanding systems and interdependence is just so critical!

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A single nerve tract deep within the brain of mice influences the animal's tendency to socialize

A single nerve tract deep within the brain of mice influences the animal's tendency to socialize | Amazing Science | Scoop.it

A team of Stanford Universityinvestigators has linked a particular brain circuit to mammals’ tendency to interact socially. Stimulating this circuit — one among millions in the brain — instantly increases a mouse’s appetite for getting to know a strange mouse, while inhibiting it shuts down its drive to socialize with the stranger.


The new findings, published June 19 in Cell, may throw light on psychiatric disorders marked by impaired social interaction such as autism, social anxiety, schizophrenia and depression, said the study’s senior author, Karl Deisseroth, MD, PhD, a professor of bioengineering and of psychiatry and behavioral sciences. The findings are also significant in that they highlight not merely the role of one or another brain chemical, as pharmacological studies tend to do, but rather the specific components of brain circuits involved in a complex behavior. A combination of cutting-edge techniques developed in Deisseroth’s laboratory permitted unprecedented analysis of how brain activity controls behavior.


Deisseroth, the D.H. Chen Professor and a member of the interdisciplinary Stanford Bio-X institute, is a practicing psychiatrist who sees patients with severe social deficits. “People with autism, for example, often have an outright aversion to social interaction,” he said. They can find socializing — even mere eye contact — painful.


Deisseroth pioneered a brain-exploration technique, optogenetics, that involves selectively introducing light-receptor molecules to the surfaces of particular nerve cells in a living animal’s brain and then carefully positioning, near the circuit in question, the tip of a lengthy, ultra-thin optical fiber (connected to a laser diode at the other end) so that the photosensitive cells and the circuits they compose can be remotely stimulated or inhibited at the turn of a light switch while the animal remains free to move around in its cage.

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Software Used for Facial Recognition Teases Out Secret Messages Hidden on Bird Eggs

Software Used for Facial Recognition Teases Out Secret Messages Hidden on Bird Eggs | Amazing Science | Scoop.it

Some bird eggs have visual signatures that help them distinguish they own clutch from impostor cuckoo .


For most honest bird species, brood parasites like the cuckoo are no joke. These sneaky free-loaders comprise about one percent of all bird species. Sniffing out false eggs is serious business for many birds. Brood parasites plant eggs in unsuspecting nests and leave the duped foster parents to care for their chicks—usually to the deadly detriment of the foster parents' own babies. 

Now, researchers from Harvard University and the University of Cambridge have discovered one way that bird parents likely keep an eye on their own eggs: with special visual signature. The researchers used the same kind of software that companies rely on for facial recognition and image stitching but applied that technology to hundreds of eggs of eight different parasitized bird species. They call the new program NaturePatternMatch.


The host birds, they found, have previously unrecognized egg "signatures"—essentially, secret visual cues that allow them to recognize their own among the imposters. The more intensely the bird species is targeted by cuckoos, the more complex and sophisticated their egg signatures. Some of the host birds, they found, produce exactly the same egg, whereas some show variation within their own clutch or between females within the same species. All of these methods, the team says, would likely be effective strategies for lessening the likelihood of being duped.


"The ability of Common Cuckoos to mimic the appearance of many of their hosts' eggs has been known for centuries," the researchers say in a statement. "The astonishing finding here is that hosts can fight back against cuckoo mimicry by evolving highly recognizable patterns on their own eggs, just like a bank might insert watermarks on its currency to deter counterfeiters."

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Is There A Remnant Ancient Earth Lodged Deep Inside Earth's Mantle?

Is There A Remnant Ancient Earth Lodged Deep Inside Earth's Mantle? | Amazing Science | Scoop.it

A team of scientists from Harvard University believe that have found evidence that an ancient Earth exists inside the Earth.


The team believes that a previously unexplained isotopic ratio from deep within the Earth might be a signal from material from before the Earth collided with another planet-sized body, which led to the creation of the Moon. This might be an echo of an ancient Earth that existed 4.5 billion years ago, prior to the proposed collision.


The current favored theory says that the Moon was formed 4.5 billion years ago when the Earth collided with a mass the size of Mars, dubbed “Theia.” This theory states that the heat generated by the collision would have melted the whole planet before some of the debris spun off to create the Moon.


But now, the team at Harvard, led by Associate Professor Sujoy Mukhopadhyay, believe that they’ve found evidence to support that only part of the Earth melted, and that an ancient part still exists within the Earth’s mantle.


According to Professor Mukhopadhyay: “The energy released by the impact between the Earth and Theia would have been huge, certainly enough to melt the whole planet. But we believe that the impact energy was not evenly distributed throughout the ancient Earth. This means that a major part of the impacted hemisphere would probably have been completely vaporized, but the opposite hemisphere would have been partly shielded, and would not have undergone complete melting.”

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Princess and the Pea? Invisibility cloak prevents an object from being felt

Princess and the Pea? Invisibility cloak prevents an object from being felt | Amazing Science | Scoop.it

In the past years, invisibility cloaks were developed for various senses. Objects can be hidden from light, heat or sound. However, hiding of an object from being touched still remained to be accomplished. KIT scientists have now succeeded in creating a volume in which an object can be hidden from touching similar to a pea under the mattress of a princess. The results are now presented in the renowned Nature Communications journal. (DOI: 10.1038/ncomms5130)

 

Magicians and illusionists make things disappear by means of a skilled use of mental delusions and diversionary tactics. KIT researchers, by contrast, use invisibility cloaks based on the laws of physics. In the past years, various physical invisibility cloaks were developed. Optical invisibility cloaks, for instance, make objects appear invisible, while others appear to let heat or sound pass uninfluenced. A completely new type of invisibility cloak is the mechanical one developed by KIT scientists. It prevents an object from being touched.

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MIT ranking of 10 New Breakthrough Technologies in 2014

MIT ranking of 10 New Breakthrough Technologies in 2014 | Amazing Science | Scoop.it

Technology news is full of incremental developments, but few of them are true milestones. Here we’re citing 10 that are. These advances from the past year all solve thorny problems or create powerful new ways of using technology. They are breakthroughs that will matter for years to come.


Agricultural Drones

Relatively cheap drones with advanced sensors and imaging capabilities are giving farmers new ways to increase yields and reduce crop damage.


Ultraprivate Smartphones

New models built with security and privacy in mind reflect the Zeitgeist of the Snowden era.


Brain Mapping
A new map, a decade in the works, shows structures of the brain in far greater detail than ever before, providing neuroscientists with a guide to its immense complexity.


Neuromorphic Chips
Microprocessors configured more like brains than traditional chips could soon make computers far more astute about what’s going on around them.


Genome Editing
The ability to create primates with intentional mutations could provide powerful new ways to study complex and genetically baffling brain disorders.


Microscale 3-D Printing
Inks made from different types of materials, precisely applied, are greatly expanding the kinds of things that can be printed.


Mobile Collaboration
The smartphone era is finally getting the productivity software it needs.


Oculus Rift
Thirty years after virtual-reality goggles and immersive virtual worlds made their debut, the technology finally seems poised for widespread use.


Agile Robots
Computer scientists have created machines that have the balance and agility to walk and run across rough and uneven terrain, making them far more useful in navigating human environments.


Smart Wind and Solar Power
Big data and artificial intelligence are producing ultra-accurate forecasts that will make it feasible to integrate much more renewable energy into the grid.

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Marc Kneepkens's curator insight, June 20, 2014 8:22 PM

Very interesting information on what is happening with cutting edge science and technologies.

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Theoretical physics: The origins of space and time

Theoretical physics: The origins of space and time | Amazing Science | Scoop.it

Many researchers believe that physics will not be complete until it can explain not just the behavior of space and time, but where these entities come from.


“Imagine waking up one day and realizing that you actually live inside a computer game,” says Mark Van Raamsdonk, describing what sounds like a pitch for a science-fiction film. But for Van Raamsdonk, a physicist at the University of British Columbia in Vancouver, Canada, this scenario is a way to think about reality. If it is true, he says, “everything around us — the whole three-dimensional physical world — is an illusion born from information encoded elsewhere, on a two-dimensional chip”. That would make our Universe, with its three spatial dimensions, a kind of hologram, projected from a substrate that exists only in lower dimensions.


This 'holographic principle' is strange even by the usual standards of theoretical physics. But Van Raamsdonk is one of a small band of researchers who think that the usual ideas are not yet strange enough. If nothing else, they say, neither of the two great pillars of modern physics — general relativity, which describes gravity as a curvature of space and time, and quantum mechanics, which governs the atomic realm — gives any account for the existence of space and time. Neither does string theory, which describes elementary threads of energy.


Van Raamsdonk and his colleagues are convinced that physics will not be complete until it can explain how space and time emerge from something more fundamental — a project that will require concepts at least as audacious as holography. They argue that such a radical reconceptualization of reality is the only way to explain what happens when the infinitely dense 'singularity' at the core of a black hole distorts the fabric of space-time beyond all recognition, or how researchers can unify atomic-level quantum theory and planet-level general relativity — a project that has resisted theorists' efforts for generations.


“All our experiences tell us we shouldn't have two dramatically different conceptions of reality — there must be one huge overarching theory,” says Abhay Ashtekar, a physicist at Pennsylvania State University in University Park. Finding that one huge theory is a daunting challenge.


Nature explores some promising lines of attack — as well as some of the emerging ideas about how to test these concepts (see 'The fabric of reality').

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Guillaume Decugis's curator insight, June 24, 2014 10:52 AM

A recap on the unifying theories that could explain the fabric of our universe.

Tekrighter's curator insight, June 25, 2014 9:36 AM

Gravity as thermodynamics reinforces the idea of gravity as an emergent property of space-time...

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'Superfluid spacetime' points to unification of physics

'Superfluid spacetime' points to unification of physics | Amazing Science | Scoop.it
Thinking of space and time as a liquid might help reconcile quantum mechanics and relativity.


If spacetime is like a liquid — a concept some physicists say could help resolve a confounding disagreement between two dominant theories in physics — it must be a very special liquid indeed. A recent study compared astrophysical observations with predictions based on the notion of fluid spacetime, and found the idea only works if spacetime is incredibly smooth and freely flowing — in other words, a superfluid.


Thinking of spacetime as a liquid may be a helpful analogy. We often picture space and time as fundamental backdrops to the universe. But what if they are not fundamental, and built instead of smaller ingredients that exist on a deeper layer of reality that we cannot sense? If that were the case, spacetime’s properties would “emerge” from the underlying physics of its constituents, just as water’s properties emerge from the particles that comprise it. “Water is made of discrete, individual molecules, which interact with each other according to the laws of quantum mechanics, but liquid water appears continuous and flowing and transparent and refracting,” explains Ted Jacobson, a physicist at the University of Maryland, College Park. “These are all ‘emergent’ properties that cannot be found in the individual molecules, even though they ultimately derive from the properties of those molecules.”


Physicists have been considering this possibility since the 1990s in an attempt to reconcile the dominant theory of gravity on a large scale — general relativity — with the theory governing the very smallest bits of the universe—quantum mechanics. Both theories appear to work perfectly within their respective domains, but conflict with one another in situations that combine the large and small, such as black holes (extremely large mass, extremely small volume). Many physicists have tried to solve the problem by 'quantizing' gravity — dividing it into smaller bits, just as quantum mechanics breaks down many quantities, such as particles’ energy levels, into discrete packets. “There are many attempts to quantize gravity—string theory and loop quantum gravity are alternative approaches that can both claim to have gone a good leg forward,” says Stefano Liberati, a physicist at the International School for Advanced Studies (SISSA) in Trieste, Italy. “But maybe you don’t need to quantize gravity; you need to quantize this fundamental object that makes spacetime.”


Liberati, along with his colleague Luca Maccione of Ludwig Maximilian University in Munich, recently explored how that idea would affect light traveling through the universe. An emergent spacetime, one that acted like a fluid, would not be immediately distinguishable from the spacetime of any other theory. But in extreme situations, such as for very energetic light particles, Liberati and Maccione found that some differences would be noticeable. In fact, by examining observations of high-energy photons flying across the universe from the Crab Nebula, the physicists were able to rule out certain versions of emergent spacetime, finding that if it is a fluid at all, it must be a superfluid. The researchers published their results in Physical Review Letters1 in April.


In this analogy particles would travel through spacetime like waves in an ocean, and the laws of fluid mechanics — condensed-matter physics — would apply. Previously physicists considered how particles of different energies would disperse in spacetime, just as waves of different wavelengths disperse, or travel at different speeds, in water. In the latest study Liberati and Maccione took into account another fluid effect: dissipation. As waves travel through a medium, they lose energy over time. This dampening effect would also happen to photons traveling through spacetime, the researchers found. Although the effect is small, high-energy photons traveling very long distances should lose a noticeable amount of energy, the researchers say.


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