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Blue Baby Breakthrough

A story of perseverance and diversity that led to medical history being made. Happy Birthday, Dr. Taussig! 

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Rajini Rao originally shared to Making Sense of Science:
 
Affairs of the Heart: Dr. Helen Taussig 

❤  On a late November day in 1944, bright sunlight streamed upon the blue-tinged body of 18 month old Eileen Saxon, who was hovering near death. Born with a congenital heart defect that prevented her blood from being oxygenated by her lungs, she now weighed little more than 9 pounds. Across the ocean, World War II raged on, but at the +Johns Hopkins University hospital in Baltimore, another type of history was being made. Under the gaze of 706 doctors gathered around, Dr. Alfred Blalock meticulously rerouted an artery heading to the child's arm, back to the lungs giving the oxygen-starved blood a second chance of rejuvenation. The anesthesiologist cried out in astonishment as Eileen's lips turned from blue to a healthy red. That was the start of a successful procedure that would cure thousands of "blue babies" in the brand new era of heart surgery that followed. Today, we remember Dr. Helen Taussig, whose brilliant idea it was that set the stage.

❤ Born on this day, May 24, in 1898, Helen took medical classes at both Harvard and Boston Universities although neither would award her a degree because of her gender. Worse, she was forbidden to speak to her male colleagues in histology class because of fears that she would "contaminate" them. She completed her MD degree at Johns Hopkins and there, as a pediatric cardiologist did extensive work with anoxemia, or blue baby syndrome. She noticed that blue babies with an additional heart defect (called PDA) fared better, and that a shunt that mimicked PDA could be the solution. She pitched the idea of getting more blood to the lungs much "as a plumber changes pipes around" to surgeon Alfred Blalock and his technician Vivien Thomas. Thomas, a black man whose education did not go beyond high school, practiced the surgery in the animal lab and after modifying instruments for use in humans, coached Dr. Blalock through the first hundred surgeries in infants. In 1976, Hopkins awarded him an honorary doctorate. Sadly, little Eileen became cyanotic again in a few months and did not survive past 2 years even though other babies would go on to live healthy lives. Today, a modified version of the shunt is performed using a synthetic Gore-Tex graft (lower right image). 

¸¸.•*¨*•♫ Happy Birthday, Dr. Taussig!  

Image Note: Helen Taussig became deaf in later years, and actually used her fingers rather than a stethoscope to feel the rhythm of heartbeats.

More: http://en.wikipedia.org/wiki/Helen_B._Taussig_
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Day of the Dog

New DNA evidence suggests that arctic breeds of dogs had another, ancient origin. Thanks +Chad Haney for shedding some light on man's best friend!

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Taimyr wolf and the origins of dog
There's an ongoing debate about where and when dogs originated. The when part might be closer to an answer now. Genetic drift is used by evolutionary biologist to try to recreate the lineage of species. The discovery of a 35,000-year-old wolf rib bone in the Taimyr peninsula in northern Siberia was the key to this story. The DNA from that bone suggests that it diverged from a common ancestor of present-day wolves and dogs near the beginning of the domestic dog lineage. Their technique uses genetic drift of 'regular' DNA and mitochondrial DNA.

► Genetic Drift
There are non-lethal random mutations in DNA that survive to the next generation due to natural selection and sometimes due to 'luck'. Surviving by natural selection makes sense, a mutation affords an advantage so that offspring should excel and survive. Genetic drift is when a mutation doesn't necessarily result in an advantage but is nevertheless passed on 'by chance'. Tracing these mutations help create a lineage for evolutionary biologists.

► Mitochondrial DNA vs. Nuclear DNA
Mitochondria are the energy power plants inside cells. They have a few genes necessary for oxidative phosphorylation, which is a fancy term for making energy. The nucleus of the cell is where the chromosomes are. Nuclear DNA is the DNA that you hear about in the news, for example in forensic science. In the figure below, you can see that mitochondrial DNA is passed on only by the mother while nuclear DNA is passed along by both parents. Genetic drift in mitochondrial DNA is much slower and helps refine the lineage of a species. It is slower because it is only inherited by half of the genetic source, i.e., the mother.

You can read a summary of the article in layman's terms here:
Arctic find confirms ancient origin of dogs
http://news.sciencemag.org/biology/2015/05/arctic-find-confirms-ancient-origin-dogs

Full article and source of the very cool graphical abstract:
Ancient Wolf Genome Reveals an Early Divergence of Domestic Dog Ancestors and Admixture into High-Latitude Breeds
Skoglund et al
Current Biology May 2015
http://www.cell.com/current-biology/abstract/S0960-9822(15)00432-7

Source for the mitochondria DNA figures:
University of California Museum of Paleontology's Understanding Evolution (http://evolution.berkeley.eduhttp://goo.gl/WZgKRV

A bit more reading:
How the wolf became the dog (full article behind paywall)
http://news.sciencemag.org/environment/2015/04/how-wolf-became-dog

Late for #FidoFriday  but always on time for #ScienceEveryday  
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Color Us Fractally

A colorful way to start your +ScienceSunday with a tutorial on fractals from our resident mathematician +Richard Green . Thanks, Richard, for another stunning post. 

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Richard Green originally shared to Mathematics:
 
The Gamma Function and Fractal Factorials!

This fractal image by Thomas Oléron Evans was created by using iterations of the Gamma function, which is a continuous version of the factorial function.

If n is a positive integer, the factorial of n, n!, is defined to be the product of all the integers from 1 up to n; for example, 4!=1x2x3x4=24. It is clear from the definition that (n+1)! is the product of n+1 and n!, but it is not immediately clear what the “right” way is to extend the factorial function to non-integer values.

If t is a complex number with a positive real part, the Gamma function Γ(t) is defined by integrating the function x^{t–1}e^{–x} from x=0 to infinity. It is a straightforward exercise using integration by parts and mathematical induction to prove that if n is a positive integer, then Γ(n) is equal to (n–1)!, the factorial of (n–1). Since Γ(1)=1, this gives a justification (there are many others) that the factorial of zero is 1.

Using a technique called analytic continuation, the Gamma function can then be extended to all complex numbers except negative integers and zero. The resulting function, Γ(t), is infinitely differentiable, except at the nonpositive integers, where it has simple poles; the latter are the same kind of singularity that the function f(x)=1/x has at x=0. A particularly nice property of the Gamma function is that it satisfies Γ(t+1)=tΓ(t), which extends the recursive property n!=n(n–1)! satisfied by factorials. It is therefore natural to define the factorial of a complex number z by z!=Γ(z+1).

At first, it may not seem very likely that iterating the complex factorial could produce interesting fractals. If n is an integer that is at least 3, then taking repeated factorials of n will produce a sequence that tends to infinity very quickly. However, if one starts with certain complex numbers, such as 1–i, repeated applications of the complex factorial behave very differently. It turns out that (1–i)! is approximately 0.653–0.343i, and taking factorials five times, we find that (1–i)!!!!! is approximately 0.991–0.003i. This suggests that iterated factorials of 1–i  may produce a sequence that converges to 1.

It turns out that if one takes repeated factorials of almost any complex number, we either obtain a sequence that converges to 1 (as in the case of 1–i) or a sequence that diverges to infinity (as in the case of 3). However, it is not possible to take factorials of negative integers, and there are some rare numbers, like z=2, that are solutions of z!=z and do not exhibit either type of behaviour.

By plotting the points that diverge to infinity in one colour, and the points that converge to 1 in a different colour, fractal patterns emerge. The image shown here uses an ad hoc method of colouring points to indicate the rate of convergence or divergence. The points that converge to 1 are coloured from red (fast convergence) to yellow (slow convergence), and the points that diverge to infinity are coloured from green (slow divergence) to blue (fast divergence)

Relevant links

Thomas Oléron Evans discusses these fractals in detail in a blog post (http://www.mathistopheles.co.uk/2015/05/14/fractal-factorials/) which contains this image and many others. He (and I) would be interested in knowing if these fractals have been studied before.

The applications of the Gamma function in mathematics are extensive. Wikipedia has much more information about the function here: http://en.wikipedia.org/wiki/Gamma_function

This post appears in my Mathematics collection at https://plus.google.com/collection/8zrhX

#mathematics #sciencesunday  

Various recent posts by me
Camellia flower: https://goo.gl/8WNrlu
Horse chestnut tree: https://goo.gl/FPCGI3
A Curious Property of 82000: https://goo.gl/1rVg8y
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Celestial Mergers

While a Comcast-Time Warner merger may be huge, it does not generate short bursts of gamma rays! Read what happens when a black hole merges with a neutron star in +Jonah Miller's post for #ScienceSunday  .

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Simulating Short Gamma Ray Bursts

The night sky is peppered with incredibly bright bursts of gamma rays. These so-called gamma ray bursts may be caused by a black hole eating a neutron star. Read on to learn more.

(To read this blog post in more detail, go here: http://www.thephysicsmill.com/2015/05/03/simulating-gamma-ray-bursts/)

It was the mid 1960s. The United States and the Soviet Union had recently signed the Partial Nuclear Test Ban Treaty [1], which forbid the detonation of nuclear weapons except underground. Since neither nation trusted the other, each was carefully monitoring the other for non-compliance. In particular, the United States feared that the soviets might be, I kid you not, testing bombs behind the moon [2].

Vela

The United States solved this problem with the Vela satellites [3]. When a nuclear bomb goes off, it emits a short burst of gamma rays, which are rays of extremely high energy light. The Vela satellites were gamma ray detectors in space, orbiting the Earth 65,000 miles above the surface. Figure 2 shows one of these satellites in a clean room.

The Vela satellites did detect gamma rays all right, but they didn’t come from nuclear weapons… they didn’t even come from the solar system. The satellites repeatedly detected short, very intense bursts of gamma radiation that nevertheless took too long to be from nuclear weapons blasts.

Gamma Ray Bursts

For a long time, we didn’t know anything about these events or what caused them. So we gave them the enigmatic name gamma ray bursts [4], and made up many models for what could cause them.

This changed in the late nineties, when we were able to measure X-rays and visible light emitted from the same source after the burst, which we call an afterglow. We now know that there are many causes for gamma ray bursts. Some bursts take a relatively long time and we’ve linked them to supernovae in distant galaxies [5].

The relatively shorter gamma ray bursts (creatively called short gamma ray bursts ) are less common and less extensively studied. And we therefore know a lot less about them. One popular theory [6] is that they’re caused by the merger of a black hole and a neutron star.

A Quick Aside on Neutron Stars

Neutron stars are the densest stars we know of. Figure 3 shows that a neutron star twice as massive as our sun might have a radius smaller than Manhattan. Indeed, the only thing preventing a neutron star from forming a black hole is the Pauli exclusion principle (which I wrote about here: http://www.thephysicsmill.com/2013/01/27/binary-unity-the-pauli-exclusion-principle/).

Ordinary matter is made up of mostly empty space. The radius of an atomic nucleus is about a picometer, while the radius of an atom is about an angstrom. This means that, on average, 99.9999 % of matter is empty space. Not so with a neutron star. A neutron star is made up of neutrons packed as tightly as possible, like spheres [7]. This means that in a neutron star, only about 25 % of a neutron star is empty space. (Obviously take this analogy with a grain of salt. The properties of a neutron star depend heavily on quantum mechanics and nuclear physics… so the neutrons aren’t actually packed like spheres. They’re waves. See: http://www.thephysicsmill.com/2012/12/09/the-charming-doubleness-particle-wave-duality/)

Anyway, neutron stars are incredible.

Black Hole-Neutron Star Mergers

When a black hole gets too close to a black hole, the black hole can eat it. But as I’ve discussed before, black holes are messy eaters. The matter in the neutron star gets distorted and forms an accretion disk around the black hole, which glows incredibly brightly. (see: http://www.thephysicsmill.com/2013/11/09/accretion-disk/)

As the accreting matter falls the black hole, that matter can be accelerated to incredible velocities and launched out the poles, forming an ultrarelativistic “jet.” These jets are common in many circumstances, but we believe that the jet from a black hole-neutron star merger might be the source of short gamma ray bursts [8].

There’s a long and beautiful history of studies of accretion disks and the jets they drive. And we’ve known that black-hole neutron star mergers produce accretion disks of the right type. But there’s still a lot we don’t understand about jets, accretion physics, and neutron stars [9].

The Jet Emerges: A Piece of the Puzzle

Recently, Vasileios Paschalidis, Milton Ruiz, and Stuart L. Shapiro, of the University of Illinois at Urbana-Champaign numerical relativity group, helped add a bit to our understanding. For the first time, they simulated a black hole-neutron star merger, watched as the accretion disk formed, and the relativistic jet emerged. This provides additional evidence that black-hole neutron star mergers might be the progenitors of short gamma ray bursts. Figure 4 shows snapshots of the simulation as the black hole disrupts the star, accretes the matter, and finally drives the jet.

You can find a preprint of the article, which is currently undergoing peer-review, here:  http://arxiv.org/abs/1410.7392

Now, studies like this have been attempted before. Researchers routinely run many simulations of black hole-neutron star mergers to make predictions about gravitational waves [10]. And many groups around the world have run simulations of the jets driven by black holes. However, no previous simulation has successfully observed a jet after merger. All the previous jet simulations started with an accretion disk already in place.

Paschalidis, Ruiz, and Shapiro got their jet to emerge by correctly configuring the magnetic field of the neutron star before merger. Previously, all magnetic fields were assumed to be confined only within the star, and not exist outside it. Paschalidis, Ruiz, and Shapiro argue that this isn’t particularly realistic and, by including the exterior magnetic field, the jet emerges naturally.

This is a pretty cool piece of science!

Related Reading

If you found this interesting, you might enjoy my other posts on astrophysics.

1. In this post, I describe accretion disks in more detail: http://www.thephysicsmill.com/2013/11/09/accretion-disk/

2. In this post, I describe how planets form: http://www.thephysicsmill.com/2014/06/01/planets-form/

3. In this post, I describe the relativistic jets of active galactic nuclei: http://www.thephysicsmill.com/2015/04/02/the-long-arms-of-the-black-hole/

References
[1] https://en.wikipedia.org/wiki/Partial_Nuclear_Test_Ban_Treaty
[2] https://books.google.ca/books?id=8OfYKnsZSBUC&lpg=PA42&dq=katz%20the%20biggest%20bang&pg=PA4#v=onepage&q=katz%20the%20biggest%20bang&f=false
[3] https://en.wikipedia.org/wiki/Vela_%28satellite%29
[4] https://en.wikipedia.org/wiki/Gamma-ray_burst
[5] http://arxiv.org/abs/astro-ph/0609142
[6] http://arxiv.org/abs/astro-ph/0701874
[7] http://mathworld.wolfram.com/SpherePacking.html
[8] http://arxiv.org/abs/astro-ph/0701874
[9] http://relativity.livingreviews.org/Articles/lrr-2013-1/
[10] http://www.black-holes.org/

#science   #physics   #astrophysics   #generalrelativity   #blackhole   #neutronstar   #space   #astronomy   #computers   #simulations   #supercomputer   #ScienceSunday   #ScienceEveryDay  
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Gator Gar!

Now that's a big fish for your #ScienceSunday  catch.

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"The alligator gar is eight feet long, 254 pounds and about 44 inches around, and was caught on Lake Texoma in Marshal county last Thursday."

Alligator gars are the largest of the gar species and can live for many decades. While the 254 lb (115 kg) gar recently caught is a record for Oklahoma, the largest on record comes from Mississippi weighing 327 lbs (148 kg) with a length of 95 in (2.4 m). Texas comes in close with a record 302 lb (137 kg) alligator gar, and it is not unusual to reel in specimens over 200 lbs (91 kg). They have recently become popular for sports fishing which may contribute to their decline in the southeastern portion of its range, but some states are starting to impose limits to protect populations. While it gained its common name for the rows of large teeth, the alligator gar is not know to attack humans; however, the eggs are poisonous if ingested, and alligator gar can pose as an obstacle on water courses. Alligator gars have few predators, but the alligator is one of them.

A quick link of interest for your #ScienceSunday . Alligator gars are too cool to not make more widely known of their existence.

Sources and Further Reading
Alligator Gar (Atractosteus spatula) : TPWD
https://tpwd.texas.gov/huntwild/wild/species/alg/
Alligator Gar (Atractosteus spatula) : NatGeo
http://environment.nationalgeographic.com/environment/freshwater/alligator-gar/
OKLAHOMA-- An alligator gar caught on Lake Texoma is going down in the record books.
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Art or Science?

Can you distinguish the microscope image of basal cell carcinoma from the Van Gogh inspired quilt?

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Rajini Rao originally shared to Art or Science?:
 
Cancer or Canvas?

★ Do you see cancer cells run amok or a beautiful rendition of Van Gogh's "Starry Night"?  In this addition to my Art or Science? collection, it's hard to pick out the microscope image from the artwork it inspired. The tiny biological details revealed by researchers at the University of Michigan Center for Organogenesis are captured in larger than life quilts by Fiber Artists @ Loose Ends who raise public awareness about the importance of the arts in healthcare settings.

★ On the Left is a cross-section of mouse skin with basal cell carcinoma, the most common form of human skin cancer. The top layer of skin is stained red, collagen fibers are stained blue and the deadly tumor cells appear in the red at the bottom. On the Right, artist Carole Nicholas renders the image with fabric and stitching to simulate the Van Gogh's brushwork in a quilt.

★ This type of common skin cancer arises exclusively from the base of the hair follicle, where a niche of stem cells reside. When the hair follicle is in its growth phase, these cells are temporarily activated by the hedgehog signaling pathway. In cancer, this pathway is permanently on overdrive, due to mutations in genes known as Patched (PTCH) or Smoothened (SMO). If you're curious about the origin of these amusing gene names, especially Sonic Hedgehog, Indian Hedgehog and Tiggywinkle Hedgehog, check out +Buddhini Samarasinghe's entertaining and informative post (http://goo.gl/bhlKie)! 

REF: Hutchin et al. Sustained Hedgehog signaling is required for basal cell carcinoma proliferation and survival: conditional skin tumorigenesis recapitulates the hair growth cycle.
http://genesdev.cshlp.org/content/19/2/214.long

Image Credits: Mark Hutchin, University of Michigan
Art Quilt by Carole Nicholas, Fiber Artists@Loose Ends

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Science Sunday Digest

Enjoy your weekly roundup of science and technology, curated by +Mark Bruce !

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SciTech #ScienceSunday Digest - 18/2015.
Permalink here: http://www.scitechdigest.net/2015/05/whole-brain-staining-chemogenic-neural.html 

Whole brain staining, Chemogenic neural switching, Neuronal secrets, Single electron radio, Remote immersive telepresence, Aural parsing machines, Novel materials scaleup, Self-guided bullets, Logistical automation robots, New visual prosthesis. 

1. Whole-Brain Staining for Whole-Brain Mapping
A complex new brain-staining method called BROPA is the first of its kind able to stain an entire brain including all neurons and synaptic connections http://www.mpg.de/9161585/connectome-diagram-brain. This now raises the distinct possibility of using the now-standard block-face scanning electron microscope technique to image an entire brain, slice by slice, and stitch these images together into a complete brain connectome map. Until now brain-staining techniques have only been useful for small sections of brain tissue, which could be scanned to produce connectomes but piecing these together into whole-brain maps was infeasible. So far the technique has only been demonstrated for mouse brains and the group plan to produce a complete mouse connectome comprising 40 petabytes, but it is yet to be seen if the technique can scale to human level.

2. Chemogenic Switching of Neurons
A newly developed chemogenic technique allows neurons to be controllably switched on and off http://news.unchealthcare.org/news/2015/april/new-brain-initiative-technology-can-switch-behavior-2018on2019-and-2018off2019. The chemogenic technique essentially represents an improved DREADD technology (http://en.wikipedia.org/wiki/Receptor_activated_solely_by_a_synthetic_ligand) in which neural cell-wall receptors were modified and engineered to be sensitive to specific synthetic molecules or drugs. Subsequently, these receptors - and the firing of the neurons they adorn - could be activated or deactivated by adding or removing the synthetic molecule from the animal’s system, and in this case two different receptors were introduced to mature mice via viral-administered gene therapies. In different tests both voracious feeding and drug addiction behaviour could be switched on and off at will.

3. A Duo of Fundamental Neuron Function Discoveries
The first of these sheds new light on exactly how neurons form connections and memories at the molecular and cellular level http://news.vanderbilt.edu/2015/04/new-insight-into-how-brain-makes-memories/; a specific signalling protein called Asef2 that actively promotes synapse formation by promoting outgrowths of actin from the neual cytoskeleton - its lack can lead to a range of disorders. The second shows that neurons make methylation alterations to their DNA on a regular and on-going basis http://www.hopkinsmedicine.org/news/media/releases/neurons_constantly_rewrite_their_dna; this is believed to be important for maintaining consistent synaptic signalling activity by modulating the activity of key signalling proteins. 

4. Detecting Radio Waves from a Single Electron
For the first time radio waves have been detected from a single spinning electron http://news.sciencemag.org/physics/2015/04/physicists-detect-radio-waves-single-electron via new ultra-sensitive experimental techniques that involve trapping single electrons ejected by radioactive samples in cusomised wave-guides. As cool as this is the group ultimately hope to use the technique to perform the most accurate measurements to date for determining the mass of a neutrino. I wonder about the reverse: using a similar setup to influence and control a single electron . . . or a neutrino. 

5. Towards True Immersive Telepresence
An Oculus-linked robotic system is edging towards the first true immersive remote telepresence system in which a user can wear a VR headset and receive binocular video input from a distant, remote robotic system that mimics the movement of the users body and head http://spectrum.ieee.org/automaton/robotics/robotics-hardware/upenn-dora-platform. The key to maintaining the feeling of immersion and presence in the remote location is minimal and unnoticeable lag between you moving your head, the robot moving its “head” in exactly the same way, and an updated video feed from the cameras arriving on the headset. 20ms lag is not perceptible and 60ms is considered an upper limit; the group currently have 70ms but hopes to drop this in the near future. 

6. Deep Learning and Aural Parsing
Software arising from deep neural networks has now been demonstrated able to separate human voices from background noise in a wide range of songs (often referred to as the cocktail party problem after the ease with which humans can do the same) http://www.technologyreview.com/view/537101/deep-learning-machine-solves-the-cocktail-party-problem/. The promise here isn’t just a next-gen karaoke machine able to remove the vocals from any and all songs of choice. This should also help make better hearing aids, bluetooth headsets, video transcripts, and other applications we haven’t thought of yet. 

7. Scaling-Up Novel Materials: Semiconductors & Metallic Glass
A couple of interesting scale-up advances this week. First, a new fabrication technique called metal organic chemical vapour deposition can successfully produce wafer-scale atomically-thin (3 atoms) films of molybdenum disulfide or tungsten diselenide for high-performance semiconductor applications http://spectrum.ieee.org/nanoclast/semiconductors/materials/novel-process-promises-atomically-thin-semiconductors-for-electronics. Second, a new manufacturing process allows spinel (magnesium aluminate) to be produced in sheets up to 30 inches wide http://www.nrl.navy.mil/media/news-releases/2015/transparent-armor-from-nrl-spinel-could-also-ruggedize-your-smart-phone; spinel is a transparent mineral that is much tougher, stronger, and harder than glass - think display screens, camera lenses, building and car windows, etc. 

8. The Latest Self-Guided Bullets from DARPA
DARPA’s new EXACTO bullet is a self-guided 0.50 caliber round that can adjust its trajectory mid-flight http://gizmodo.com/watch-darpas-scary-self-guided-bullets-swerve-to-hit-mo-1700601163. In the demonstration video you can see the bullet not only move to allow a trained sniper to hit a moving target, and not only move to allow a novice shooter to hit a moving target but, indeed to move and swerve mid flight to hit a target that starts moving after the bullet has been fired. I’m just imagining swarms of military drones that shoot and never miss. 

9. Another Industrial Automation Entrant
This week Fetch Robotics announced a duo of new robots called Fetch and Freight to tackle the logistics market http://spectrum.ieee.org/automaton/robotics/industrial-robots/fetch-robotics-introduces-fetch-and-freight-your-warehouse-is-now-automated. The duo are intended to form a team in a warehouse, with the slower Fetch and its mobile manipulator shelf-picking arm confined to zones, and Freight a faster smaller unit zipping around between Fetches and a loading point. It’s good to see competition heating up in this space with the likes of Kiva and to a lesser extent ReThink for example. I also can’t resist a call-out to Stanford’s microtug robots able to 2,000 times their weight via novel controllable adhesive technology http://nextbigfuture.com/2015/04/tiny-bots-can-drag-2000-times-their.html

10. A Vision Implant Powered by Light
A company called Pixium Vision is launching a new visual prosthetic that is powered by light and enables the blind to see http://spectrum.ieee.org/tech-talk/biomedical/bionics/blind-patients-will-soon-try-a-new-bionic-eye. The core of the system is based on a small chip that is implanted behind the retina and which includes pixels that have both a photodiode and retina-stimulating electrode; the person wears video glasses that capture the view in front of them and convert this into an infrared version that is beamed into the persons eyes which serves to both provide power and stimulate the retina. Tests in rats confirm restoration of 20/250 vision and they hope to soon achieve 10/120, below the limit of legal blindness. 

Archive: http://www.scitechdigest.net/2015/05/whole-brain-staining-chemogenic-neural.html
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Bee-guiling Science

A spectacular photo (can you spot the bee?) combined with some ruminations on circadian clocks, bees and epigenomes makes for a lovely #ScienceSunday  read. Thanks, +Larry Mayer .

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The Incredible Bittersweetness of Bee-ing

On a bright spring day in Saguaro National Park (Tucson, Arizona) the giant cacti bloom their laurels,  honey bees assume their circadian tasks, and I ponder my own perceptions and how to express them in images.  The sense of time genetically encoded into many life forms collectively referred to as the circadian clock is somewhat socially plastic in honey bees as some members of the bee social structure, such as nurse bees, may work around the clock. The variability of gene expression under environmental factors which are social rather than physical, has profound implications for all social life forms.  For example,  “disturbing” a bee hive, which we interpret to mean that bees “feel threatened”, causes an aggressive response in bees.  Scientists, discovered the chemical trigger in bees, the "alarm pheromone" isopentyl acetate, induces an instantaneous aggressive response.  But what is more profound is the discovery that the exposure to the alarm pheromone also induces widespread changes at the genetic level which might result in permanent behavioral changes. The ramifications for human social behavior are both complex and profound.  Researchers have already found compelling evidence to suggest that social and emotional processes in humans, once thought to be principally modulated by endogenous oxytocin systems may be controlled instead by epigenetic processes as well.  In the end, I have a color photograph.

background: 
http://www.pnas.org/content/106/36/15400.full.pdf
http://www.pnas.org/content/112/11/3308.full.pdf?with-ds=yes

#sciencesunday   #SaguaroNationalPark #epigenetics
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Gaming On Your Mind?

Our teenage kids, and some of us adults too, are going to be happy with this #ScienceSunday  story! 

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Terra-fic Tiling

+Richard Green explains how Penrose or hexagonal tiles can be used in cartography. 

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Penrose Land Cover by Daniel P. Huffman

This land cover map of the continental United States was produced by Daniel P. Huffman using Penrose tiles.

A more traditional way to do this would be to use the technique of hexagonal binning, which achieves a similar result by using hexagonal cells, as in a honeycomb. It is possible to tile the entire plane using either identical hexagonal tiles or Penrose tiles. A key difference between the two is that the hexagons will produce a tiling with full translational symmetry, whereas the Penrose tiles will not.

Daniel Huffman recently remarked that “Penrose tilings are the new hexbins”. You can find this map, and some others of the same type, on Huffman's Twitter page: https://twitter.com/pinakographos

Wikipedia seems not to have a good description of hexbins, but cartographer Zachary Forest Johnson wrote a nice blog post about them a few years ago, which you can find here: http://indiemaps.com/blog/2011/10/hexbins/

Wikipedia has more on Penrose tilings here: http://en.wikipedia.org/wiki/Penrose_tiling

I have posted about Penrose tilings and related tilings several times, for example here: https://plus.google.com/101584889282878921052/posts/dhPpRnwNmsR

#mathematics #cartography #sciencesunday

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Science Hangout on Air

Join +Science on Google+ on a fascinating HOA coming up this week.

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Please join us on 5/5 for a +Science on Google+ HOA with Dr.+Miguel Nicolelis, Professor of Neurobiology, Biomedical Engineering, Psychology, and Neuroscience at +Duke University, and founder of Duke's Center for Neuroengineering. Dr. Nicolelis is a pioneer in neuronal population coding (simultaneously recording from hundreds to thousands of neurons), Brain Machine Interface (controlling robotic or avatar limbs with thoughts), neuroprosthetics (prosthetic limbs that directly communicate with sensory and motor cortices), and Brain to Brain Interface (tactile or visual information encoded by rat 1 is decoded by rat 2). Dr. Nicolelis has published over 200 peer-reviewed articles, with many of these publications appearing in high impact journals such as Nature, Science, and Proceedings of the National Academy of Sciences (see below for a short list of publications). More recently, Dr. Nicolelis’ research made it possible for a quadriplegic child to use his mind to control a bionic exoskeleton and kickoff the opening game at the 2014 FIFA World Cup.

RSVP “yes” to add this event to your calendar. We will open up the Q & A app so feel free to post your questions on this event post or by using the app during the hangout.

Relevant Links:
Faculty page: http://goo.gl/qs8NfM 
Lab page: http://www.nicolelislab.net 
2012 Ted Talk: http://goo.gl/kxCxT8 
2014 Ted Talk: http://goo.gl/23OqmV 
Book: http://goo.gl/x7Kg5J 

Relevant Readings (see http://goo.gl/nQadag for a more exhaustive list):

Schwarz D, Lebedev MA, Tate A, Hanson T, Lehew G, Melloy J, Dimitrov D, Nicolelis MAL. Chronic, Wireless Recordings of Large Scale Brain Activity in Freely Moving Rhesus Monkeys. Nat. Methods doi:10.1038/nmeth.2936, 2014.

Thomson EE, Carra R, Nicolelis MAL. Perceiving Invisible Light through a Somatosensory Cortical Prosthesis. Nat. Commun.10.1038/ncomms2497, 2013.

Ifft P, Shokur S, Li Z, Lebedev MA, Nicolelis MAL. A Brain-Machine Interface Enables Bimanual Arm Movements in Monkeys. Sci. Transl. Med. 5: 210, DOI:10.1126/scitranslmed.3006159, 2013.

Shokur S, O’Doherty J.E., Winans J.A., Bleuler H., Lebedev M.A., Nicolelis M.A.L. Expanding the primate body schema in sensorimotor cortex by virtual touches of an avatar. Proc. Natl. Acad. Sci. 110: 15121-6, doi: 10.1073/pnas.1308459110, 2013.

O’Doherty JE, Lebedev MA, Ifft PJ, Zhuang KZ, Shokur S, Bleuler H, Nicolelis MAL. Active tactile exploration enabled by a brain-machine-brain interface. Nature 479: 228-231, 2011.

Fuentes R, Petersson P, Siesser WB, Caron MG, Nicolelis MAL. Spinal Cord Stimulation Restores Locomotion in Animal Models of Parkinson’s disease. Science 323: 1578-82, 2009.

Pereira A, Ribeiro S, Wiest M, Moore LC, Pantoja J, Lin S-C, Nicolelis MAL. Processing of tactile information by the  hippocampus. PNAS 104: 18286-18291 (Epub) November 2007.

Krupa DJ, Wiest, MC, Laubach M, Nicolelis MAL Layer specific somatosensory cortical activation during active tactile discrimination   Science 304: 1989-1992, 2004.

Nicolelis MAL, Dimitrov DF, Carmena J, Crist R, Lehew G, Kralik J, Wise S. Chronic, multi-site, multi-electrode recordings in macaque monkeys. PNAS 100: 11041-11046, 2003.

Nicolelis MAL. Actions from thoughts. Nature 409: 403-407, 2001.
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Neuroscience Blog

We're delighted that +Brad Esau has shared his neuroscience blog with us, for #ScienceSunday  .

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Okay, I thought #sciencesunday might make a good time to re-introduce my neuroscience blog.

As the name implies, A Layman's Guide to Your Inner Galaxies, my blog is to attempt to make the beauties and wonders of the human brain and the philosophical questions that arise in its study more accessible to the general public.

I was very enthused with this project when I launched it in late 2013 but life and health issues got in the way and I had to allow it to fall fallow for over a year.

But my enthusiasm never waned and I am now going to try keep it active with new posts. For now I'm just recycling some old material that I had originally written for Taming the Polar Bears (but which now falls outside of my direction there).

#consciousness #neuroscience #brain  
Consciousness Explained Part One Okay, one of my favourite subjects about the brain – consciousness! There are a couple of reasons I want to talk about consciousness. Firstly, and most importantly, I would like my de...
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Consciousness explained is the title of Daniel Dennett's book on the subject, a real good read I'd recommend to anyone.  I'd rather believe in what he says about having a multi-draft model of consciousness that's continuously redrafted.  We have psycho-neural identities apparently, look it up
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Official page of #ScienceSunday and #ScienceEveryday (brought to you by Robby Bowles, Allison Sekuler, Rajini Rao, Chad Haney, Buddhini Samarasinghe, Aubrey Francisco, and Carissa Braun)
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You have found the official page for #ScienceSunday (co-curated by Robby Bowles, Allison Sekuler, Rajini Rao, Chad HaneyBuddhini SamarasingheAubrey Francisco, and +Carissa Braun)! Post anything related to science and tag it with #ScienceSunday, +ScienceSunday, and each curator to ensure we see your post. If you are a photographer, post a science related image and explain why it relates to science to you - doesn't need to be too specific (science is all around us!). If you are not a photographer, simply post anything related to science - drawings, movies, songs, and text are all welcome. Regardless of the type of post, feel free to add your 2 cents into a discussion in the comments. We always have some great posts with amazing images, great science information, and a lot of interesting conversations, and we're looking forward to even more in the weeks to come. If you miss the "Sunday" in #ScienceSunday, feel free to tag with #ScienceEveryday - we try to monitor those posts as well.