Bumblebees’ Little Hairs Can Sense Flowers’ Electric Fields
Flowers generate weak electric fields, and a new study shows that bumblebees canactually sense those electric fields using the tiny hairs on their fuzzy little bodies.
“The bumblebees can feel that hair bend and use that feeling to tell the differencebetween flowers,” says Gregory Sutton, a Royal Society University Research Fellow atthe University of Bristol in the United Kingdom.
People used to think that perceiving natural electric fields was something that animalsonly did in water. Sharks and eels can do it, for example. The platypus and spinyanteaters were the only land critters known have electroreceptive organs, but thesehave to be submerged in water in order to work.
Then, a few years ago, Sutton and his colleagues showed that bumblebees could senseelectric fields in the air.
“There is, all the time, a background electric field in the atmosphere,” says Sutton,”Any plant that’s connected to the ground will generate its own electric field just byinteractions with the atmosphere.”
He wondered if bumblebees could sense those electric fields and use them in someway. So his team tested that idea with the help of a bunch of almost identical artificialflowers.
The scientists took half of the flowers and put 30 volts on them, then filled them withsugar water. The other flowers were filled with a bitter liquid. “And the bees willeventually learn to go to the ones that are charged to 30 volts,” says Sutton.
When they turned off the voltage, the bees lost the ability to differentiate between theflowers and began to forage randomly, showing that the bees really were relying onthose electric fields.
But how were the bumblebees able to sense them? That’s what the researchers tackedin their latest study, described in the Proceedings of the National Academy of Sciences.
“We used a laser beam that could measure small motions of an antenna or a hair, andthat’s how we measured how much the air and the antenna moved in response to anelectric field,” says Sutton.
They also stuck a very fine electrode wire into the nerve at the socket of the bottom of ahair to record the activity of nerve cells there.
“They’ve got these really fuzzy hairs all over their body, and when they approachsomething with an electric field, that electric field will bend the hairs on their body,”says Sutton. And that bending generates a nerve signal.
The results suggest that bumblebees can sense an electric fields produced by a flowerthat’s up to 55 centimeters (nearly 22 inches) away. But that’s under ideal conditionsin the lab—Sutton says 10 centimeters or so (about 4 inches) is more likely in the realworld.
“I’m very excited by this because these little mechanically-sensitive hairs are commonall over the insect world,” says Sutton. “I think this might be something we see in moreinsects than just bumblebees.”
“Basically this just adds to the long list of incredible things that bees can do,” saysRobert Gegear, who studies pollinating insects at Worcester Polytechnic Institute inWorcester, Massachusetts.
He says it’s unclear if bees really use electric fields in the real world, where flowershave a ton of other compelling features like color and smell.
“And so the one question I have is ‘What is the functional relevance?’— not just fromthe bee side but from the plant side as well,” says Gegear.
For all we know, Gegear says, bumblebees may detect electric fields for something thathas nothing to do with flowers, like navigation or communication.
HTC’s long rumoured smartwatch has been delayed once again, according to noted leaker Evan Blass.
In his latest tweet on the subject, dated to late last week, Blass says, in colourful language, that the wearable’s release date has been pushed back to this fall.
This is just the latest delay for a device that has been pushed back a number of times already. HTC has reportedly been working on this smartwatch since 2013. In February, Blass said the company was prepared to unveil the device alongside its latest smartphone, the HTC 10.
He then revised that outlook in a later tweet, noting the watch’s unveiling waspushed back to the start of June.
Now it looks like HTC is waiting for the release of Android Wear 2, which Google unveiled at its annual I/O developer conference earlier in the month.
This isn’t the first time HTC has taken its time getting a wearable out into the market. Like its upcoming smartwatch, the company’s fitness band was delayed multiple times before it was announced as the Under Armour Band. The band, which comes optionally as part of the company’s comprehensive fitness platform UA HealthBox, came out in Canada last week.
Patriot Announces 2TB Ignite SSD
TAIPEI, Taiwan – May 30, 2016 – Patriot, a leading manufacturer of high performance computer memory, SSDs, gaming peripherals, consumer flash storage solutions and mobile accessories, today introduced a 2TB addition to its performance solid state drive (SSD) line, the Ignite. Patriot looks to fulfill the ever-growing demand for increased amounts of storage in consumer PCs.
Patriot originally launched the Ignite SSD in January of 2015 with top performing speeds and capacities of 480GB and 960GB. Since then, Patriot has added the addition of a 240GB capacity and now a multi-terabyte capacity to tackle even the most taxing data loads. With the Ignite 2TB SSD consumers can load an entire library of PC games to their rig without having to unload and load games when storage runs out.
Continuing to utilize the Phison S10 controller the 2TB Ignite reaches sequential read speeds of up to 560MB/s and write speeds of up to 500MB/s, to diminish lag while loading content to the drive. Designed in a 2.5” form factor, the 2TB Ignite has a SATA III 6.0Gb/s interface and is backwards compatible with SATA II making it the ideal upgrade for those looking for a complete solution for a lack of storage space and a PC refresh to breathe life back into an old system.
“The 2TB Ignite offers consumers the fast transfer speeds expected of our Ignite line along with the extra capacity required by power users,” Said Les Henry, VP of Engineering at Patriot. “These drives are the perfect solution for those users with very large game and video libraries as well as systems being used for cloud storage.”
The Ignite 2TB is Compatible with Windows® XP, Windows Vista®, Windows, 7, Windows® 8, Windows® 8.1, Windows® 10, Mac OS X, and Linux systems. Backed by Patriot’s award winning build quality and 3-year warranty; the Patriot Ignite will deliver one of the most reliable choices in SSDs.
The 2TB Ignite SSD will be available for purchase, worldwide, starting in the 4th Quarter of 2016. For more details visit: https://patriotmemory.com.
Patriot is a leading manufacturer of high performance, enthusiast memory modules, SSDs, flash storage, gaming peripherals and mobile accessories. Founded in 1985 and headquartered in Fremont, CA, USA, Patriot is committed to technology innovation, customer satisfaction and providing the best price for performance on the market. Patriot products have become world renown for their extreme performance, reliability and innovation. Patriot sells its products through original equipment manufacturers, retailers, e-tailers and distributors throughout the world with operations in North America, South America, Asia and Europe.
Lithium-Ion Battery Expert Jeff Dahn About To Start At Tesla Motors
As part of its ongoing expansion efforts following the great success of the Model 3 reveal, andas reported a year ago, Tesla has secured an exclusive contract with the noted battery researcher Jeff Dahn (of Dalhousie University in Nova Scotia).
The new contract begins on June 8th, and will see Dahn working to increase the performance of the company’s (already cutting-edge) batteries. Dahn will reportedly be doing “whatever it takes” to improve performance.
Jeff Dahn was quoted by Quartz as saying that the research goals for his work with Tesla are pretty much the standard ones in the industry — high energy density, low cost, and a long working life. The “whatever it takes” mentioned above apparently originated in a conversation that Dahn had with Tesla’s battery division head Kurt Kelty.
“Those are the goals, and that’s how we’re going to do it,” Dahn commented. “We’re open to anything that makes sense.”
Dahn is certainly an interesting hire. Especially when considering that his most famous work to date has been with regard to a different battery chemistry (NMC) than the one that Tesla uses currently (NCA). Interesting announcements are now probably already in the offing…
As mentioned at the start of the article, Tesla’s been on something of a hiring spree lately — following the speeding up of Model 3 production plans, and some internal housecleaning. For information on those hires and departures, see:
How to erase bad memories and enhance good ones
May 27, 2016
Imagine if people with dementia could enhance good memories or those with post-traumatic stress disorder could wipe out bad memories. A Stony Brook University research team has now taken a step toward that goal by manipulating one of the brain’s natural mechanisms for signaling involved in emotional memory: a neurotransmitter called acetylcholine.
The region of the brain most involved in emotional memory is thought to be the amygdala. Cholinergic neurons that reside in the base of the brain — the same neurons that appear to be affected early in cognitive decline — stimulate release of acetylcholine by neurons in the amygdala, which strengthens emotional memories.
Because fear is a strong and emotionally charged experience, Lorna Role, PhD, Professor and Chair of the Department of Neurobiology and Behavior, and colleagues used a fear-based memory model in mice to test the underlying mechanism of memory and the specific role of acetylcholine in the amygdala.
A step toward reversing post-traumatic stress disorder
To achieve precise control, the team used optogenetics, a research method using light, to stimulate specific populations of cholinergic neurons in the amygdala during the experiments to release acetylcholine. As noted in previous studies reported on KurzweilAI, shining blue (or green) light on neurons treated with light-sensitive membrane proteins stimulates the neurons while shining yellow (or red) light inhibits (blocks) them.
So when the researchers used optogenetics with blue light to increase the amount of acetylcholine released in the amygdala during the formation of a traumatic memory, they found it greatly strengthened fear memory, making the memory last more than twice as long as normal.
But when they decreased acetylcholine signaling (using yellow light) in the amygdala from a traumatic experience — one that normally produces a fear response — they could actually extinguish (wipe out) the memory.
Role said the long-term goal of their research is to find ways — potentially independent of acetylcholine (or drug administration) — to enhance or diminish the strength of good memories and diminish the bad ones.
Their findings are published in the journal Neuron. The research was supported in part by the National Institutes of Health.
Abstract of Cholinergic Signaling Controls Conditioned Fear Behaviors and Enhances Plasticity of Cortical-Amygdala Circuits
We examined the contribution of endogenous cholinergic signaling to the acquisition and extinction of fear- related memory by optogenetic regulation of cholinergic input to the basal lateral amygdala (BLA). Stimulation of cholinergic terminal fields within the BLA in awake-behaving mice during training in a cued fear-conditioning paradigm slowed the extinction of learned fear as assayed by multi-day retention of extinction learning. Inhibition of cholinergic activity during training reduced the acquisition of learned fear behaviors. Circuit mechanisms underlying the behavioral effects of cholinergic signaling in the BLA were assessed by in vivo and ex vivo electrophysiological recording. Photostimulation of endogenous cholinergic input (1) enhances firing of putative BLA principal neurons through activation of acetylcholine receptors (AChRs), (2) enhances glutamatergic synaptic transmission in the BLA, and (3) induces LTP of cortical-amygdala circuits. These studies support an essential role of cholinergic modulation of BLA circuits in the inscription and retention of fear memories.
- Li Jiang, Srikanya Kundu, James D. Lederman, Gretchen Y. López-Hernández, Elizabeth C. Ballinger, Shaohua Wang, David A. Talmage, Lorna W. Role. Cholinergic Signaling Controls Conditioned Fear Behaviors and Enhances Plasticity of Cortical-Amygdala Circuits. Neuron, 2016; DOI: 10.1016/j.neuron.2016.04.028
Automated top-down design technique simplifies creation of DNA origami nanostructures
May 27, 2016
MIT, Baylor College of Medicine, and Arizona State University Biodesign Institute researchers have developed a radical new top-down DNA origami* design method based on a computer algorithm that allows for creating designs for DNA nanostructures by simply inputting a target shape.
DNA origami (using DNA to design and build geometric structures) has already proven wildly successful in creating myriad forms in 2- and 3- dimensions, which conveniently self-assemble when the designed DNA sequences are mixed together. The tricky part is preparing the proper DNA sequence and routing design for scaffolding and staple strands to achieve the desired target structure. Typically, this is painstaking work that must be carried out manually.
The new algorithm, which is reported together with a novel synthesis approach in the journal Science, promises to eliminate all that and expands the range of possible applications of DNA origami in biomolecular science and nanotechnology. Think nanoparticles for drug delivery and cell targeting, nanoscale robots in medicine and industry, custom-tailored optical devices, and most interesting: DNA as a storage medium, offering retention times in the millions of years.**
Shape-shifting, top-down software
Unlike traditional DNA origami, in which the structure is built up manually by hand, the team’s radical top-down autonomous design method begins with an outline of the desired form and works backward in stages to define the required DNA sequence that will properly fold to form the finished product.
“The Science paper turns the problem around from one in which an expert designs the DNA needed to synthesize the object, to one in which the object itself is the starting point, with the DNA sequences that are needed automatically defined by the algorithm,” said Mark Bathe, an associate professor of biological engineering at MIT, who led the research. “Our hope is that this automation significantly broadens participation of others in the use of this powerful molecular design paradigm.”
The algorithm, which is known as DAEDALUS (DNA Origami Sequence Design Algorithm for User-defined Structures) after the Greek craftsman and artist who designed labyrinths that resemble origami’s complex scaffold structures, can build any type of 3-D shape, provided it has a closed surface. This can include shapes with one or more holes, such as a torus.
With the new technique, the target geometric structure is first described in terms of a wire mesh made up of polyhedra, with a network of nodes and edges. A DNA scaffold using strands of custom length and sequence is generated, using a “spanning tree” algorithm — basically a map that will automatically guide the routing of the DNA scaffold strand through the entire origami structure, touching each vertex in the geometric form once. Complementary staple strands are then assigned and the final DNA structural model or nanoparticle self-assembles, and is then validated using 3D cryo-EM reconstruction.
The software allows for fabricating a variety of geometric DNA objects, including 35 polyhedral forms (Platonic, Archimedean, Johnson and Catalan solids), six asymmetric structures, and four polyhedra with nonspherical topology, using inverse design principles — no manual base-pair designs needed.
To test the method, simpler forms known as Platonic solids were first fabricated, followed by increasingly complex structures. These included objects with nonspherical topologies and unusual internal details, which had never been experimentally realized before. Further experiments confirmed that the DNA structures produced were potentially suitable for biological applications since they displayed long-term stability in serum and low-salt conditions.
Biological research uses
The research also paves the way for designing nanoscale systems mimicking the properties of viruses, photosynthetic organisms, and other sophisticated products of natural evolution. One such application is a scaffold for viral peptides and proteins for use as vaccines. The surface of the nanoparticles could be designed with any combination of peptides and proteins, located at any desired location on the structure, in order to mimic the way in which a virus appears to the body’s immune system.
The researchers demonstrated that the DNA nanoparticles are stable for more than six hours in serum, and are now attempting to increase their stability further.
The nanoparticles could also be used to encapsulate the CRISPR-Cas9 gene editing tool. The CRISPR-Cas9 tool has enormous potential in therapeutics, thanks to its ability to edit targeted genes. However, there is a significant need to develop techniques to package the tool and deliver it to specific cells within the body, Bathe says.
This is currently done using viruses, but these are limited in the size of package they can carry, restricting their use. The DNA nanoparticles, in contrast, are capable of carrying much larger gene packages and can easily be equipped with molecules that help target the right cells or tissue.
The most exciting aspect of the work, however, is that it should significantly broaden participation in the application of this technology, Bathe says, much like 3-D printing has done for complex 3-D geometric models at the macroscopic scale.
Hao Yan directs the Biodesign Center for Molecular Design and Biomimetics at Arizona State University and is the Milton D. Glick Distinguished Professor, College of Liberal Arts and Sciences, School of Molecular Sciences at ASU.
* DNA origami brings the ancient Japanese method of paper folding down to the molecular scale. The basics are simple: Take a length of single-stranded DNA and guide it into a desired shape, fastening the structure together using shorter “staple strands,” which bind in strategic places along the longer length of DNA. The method relies on the fact that DNA’s four nucleotide letters—A, T, C, & G stick together in a consistent manner — As always pairing with Ts and Cs with Gs.
The DNA molecule in its characteristic double stranded form is fairly stiff, compared with single-stranded DNA, which is flexible. For this reason, single stranded DNA makes for an ideal lace-like scaffold material. Further, its pairing properties are predictable and consistent (unlike RNA).
** A single gram of DNA can store about 700 terabytes of information — an amount equivalent to 14,000 50-gigabyte Blu-ray disks — and could potentially be operated with a fraction of the energy required for other information storage options.
Biodesign Institute at ASU | DNA Origami
Abstract of Designer nanoscale DNA assemblies programmed from the top down
Scaffolded DNA origami is a versatile means of synthesizing complex molecular architectures. However, the approach is limited by the need to forward-design specific Watson-Crick base-pairing manually for any given target structure. Here, we report a general, top-down strategy to design nearly arbitrary DNA architectures autonomously based only on target shape. Objects are represented as closed surfaces rendered as polyhedral networks of parallel DNA duplexes, which enables complete DNA scaffold routing with a spanning tree algorithm. The asymmetric polymerase chain reaction was applied to produce stable, monodisperse assemblies with custom scaffold length and sequence that are verified structurally in 3D to be high fidelity using single-particle cryo-electron microscopy. Their long-term stability in serum and low-salt buffer confirms their utility for biological as well as nonbiological applications.