Inside the cell, an ocean of buffeting waves

Inside the cell, an ocean of buffeting waves: The cytoplasm is actually an elastic gel, it turns out, so it puts up some resistance to simple diffusion. But energetic processes elsewhere in the cell—in the cytoskeleton, especially—create random but powerful waves in the cytoplasm, pushing on proteins and organelles alike. Like flotsam and jetsam buffeted by the wakes of passing ships, suspended particles scatter much more quickly and widely than they would in a calm sea.

Scientists create artificial brain out of spongy goo | Science/AAAS | News

Scientists create artificial brain out of spongy goo | Science/AAAS | News: The rings are engineered to mimic the structure and function of the six layers of human cortical brain tissue. Scientists coaxed neurons (right) to grow around stiff, porous matrices made of silk proteins immersed in collagen gel. Then, they colored the layers with food dye and pieced them together like a jigsaw puzzle. By tweaking the size and orientation of matrix pores, researchers attempted to emulate variations of cellular structure and function in a real cortex. Unlike flat neuron cultures grown in petri dishes, the structure provides cells with something to cling to as they branch out and make connections, forming complex, 3D networks that more closely mimic real neural circuits, the authors say.

Tiny waves could build livers on a 'liquid template' - tech - 04 July 2014 - New Scientist

Tiny waves could build livers on a 'liquid template' - tech - 04 July 2014 - New Scientist: After adding a handful of starter pieces, such as silicon chips or small plastic beads, the researchers tuned the generator to various frequencies to create waves in the solution. Depending on their surface chemistry, the added particles spontaneously collected in either the crests or the valleys. Retuning the generator let the team switch between multiple patterns...

He and his colleagues cultured mouse cells and put them in the liquid template. The cells collected into little spheres that became the building blocks of larger geometric patterns. Adding blood clotting proteins to the saline solution locked the cells in place, an approach that the team is now investigating for growing liver tissue.

Muscle-powered bio-bots walk on command | News Bureau | University of Illinois

Muscle-powered bio-bots walk on command | News Bureau | University of Illinois: The new bio-bots are powered by a strip of skeletal muscle cells that can be triggered by an electric pulse...

“Skeletal muscles cells are very attractive because you can pace them using external signals,” Bashir said. “For example, you would use skeletal muscle when designing a device that you wanted to start functioning when it senses a chemical or when it received a certain signal. To us, it’s part of a design toolbox. We want to have different options that could be used by engineers to design these things.”

The design is inspired by the muscle-tendon-bone complex found in nature. There is a backbone of 3-D printed hydrogel, strong enough to give the bio-bot structure but flexible enough to bend like a joint. Two posts serve to anchor a strip of muscle to the backbone, like tendons attach muscle to bone, but the posts also act as feet for the bio-bot.

New Double Helix Visualization Revises What We Know About DNA

New Double Helix Visualization Revises What We Know About DNA: Results reaffirmed the structure first suggested by Watson and Crick in 1953. But surprisingly, the single-molecule images showed major variations in the depths and grooves in the double helix structure.

This Could Be the First Animal to Live Entirely Inside a Computer

This Could Be the First Animal to Live Entirely Inside a Computer: "Our project is to simulate as much of the important physics — or biophysics — of the C. elegans as we can, and then compare against measurements from real worms. When we say simulation, we are specifically referring to writing computer programs that use equations from physics that are applied to what we know about the worm..."

"We are currently addressing the challenge of closing the 'brain-behavior loop' in C. elegans," he says. "In other words, through this simulation we want to understand how its proto-brain controls its muscles to move its body around an environment, and then how the environment is interpreted by the proto-brain. That means leaving aside reproduction or digestion or other internal functions for now until that first part is complete. Once we get there, we will move on to these other aspects.

Hypnotic Art Shows How Patterns Emerge From Randomness in Nature | Science | WIRED

Hypnotic Art Shows How Patterns Emerge From Randomness in Nature | Science | WIRED: Turing called this the reaction-diffusion process, meaning that it’s driven by reactive molecules that can diffuse between cells. He called these molecules “morphogens”...

...a team of scientists based at Brandeis University reproduced the system Turing envisioned...

If Turing’s theory was right, then the population of cells would ultimately assume one of six different patterns...

In fact, this is mostly what the team found — they saw five of the six predicted patterns; but they also found a seventh pattern that Turing had not predicted....

Engineers design ‘living materials’ | MIT News Office

Engineers design ‘living materials’ | MIT News Office: By programming cells to produce different types of curli fibers under certain conditions, the researchers were able to control the biofilms’ properties and create gold nanowires, conducting biofilms, and films studded with quantum dots...

“It’s a really simple system but what happens over time is you get curli that’s increasingly labeled by gold particles. It shows that indeed you can make cells that talk to each other and they can change the composition of the material over time,” Lu says. “Ultimately, we hope to emulate how natural systems, like bone, form. No one tells bone what to do, but it generates a material in response to environmental signals.”

Stem cells mimic human brain : Nature News & Comment

Stem cells mimic human brain : Nature News & Comment: ...in the latest advance, scientists developed bigger and more complex neural-tissue clumps by first growing the stem cells on a synthetic gel that resembled natural connective tissues found in the brain and elsewhere in the body. Then, they plopped the nascent clumps into a spinning bath to infuse the tissue with nutrients and oxygen...

Under a microscope, researchers saw discrete brain regions that seemed to interact with one another. But the overall arrangement of the different proto-brain areas varied randomly across tissue samples — amounting to no recognizable physiological structure.

“The entire structure is not like one brain,” says Knoblich, adding that normal brain maturation in an intact embryo is probably guided by growth signals from other parts of the body. The tissue balls also lacked blood vessels, which could be one reason that their size was limited to 3–4 millimetres in diameter, even after growing for 10 months or more.

New prototype device recognizes electrical properties of infected cells as signatures of disease

New prototype device recognizes electrical properties of infected cells as signatures of disease: Several types of infection, including malaria, alter a cell's impedance...

To find out, first authors... built a microfluidic device capable of measuring the magnitude and phase of the electrical impedance of individual cells. The device is essentially a cell-counting device, similar in approach to other low-cost, portable devices being developed to diagnose illnesses such as HIV.
The challenge, however, involved optimizing the electronics to allow very accurate measurements of impedance for each cell as it passes by...
In tests of cells of four cell types—uninfected cells and infected cells at the ring, trophozoite and schizont stages—the device detected small differences in measures of magnitude and seemingly random differences in phase, but not quite enough to definitively differentiate among stages.
However, by mathematically combining the measures into an index called delta, the differences between uninfected cells and all three stages became clear.

How neurons ‘decide’ to create axons or dendrites | KurzweilAI

How neurons ‘decide’ to create axons or dendrites | KurzweilAI: They found that embryonic nerve cells manufacture a signaling enzyme called Atypical Protein Kinase C (aPKC) in two varieties: a full-length one and a shorter one...
When the researchers blocked the production of the short form, the nerve cell grew multiple axons and no dendrites. When they created an artificial abundance of the short form, dendrites formed at the expense of axons.

Watch Lab-Grown Heart Tissue Beat On Its Own [Video] | Popular Science

Watch Lab-Grown Heart Tissue Beat On Its Own [Video] | Popular Science: Using various enzymes and special cleansing detergents, the researchers stripped a mouse heart of all its cells to create a scaffold for induced pluripotent stem cells (iPS cells), adult human cells that are reprogrammed to act like embryonic cells. They treated the iPS cells taken from a skin biopsy to become multipotential cardiovascular progenitor (MCP) cells, the precursor cells that can become any of the three types of cells found in the heart...
After a period of a few weeks, the human cells had repopulated the mouse heart, and it began beating at a rate of 40 to 50 beats per minute.

Cells as living calculators - MIT News Office

Cells as living calculators - MIT News Office: MIT engineers have transformed bacterial cells into living calculators that can compute logarithms, divide, and take square roots, using three or fewer genetic parts.

Inspired by how analog electronic circuits function, the researchers created synthetic computation circuits by combining existing genetic “parts,” or engineered genes, in novel ways...


To create an analog adding or multiplying circuit that can calculate the total quantity of two or more compounds in a cell, the researchers combined two circuits, each of which responds to a different input. In one circuit, a sugar called arabinose turns on a transcription factor that activates the gene that codes for green fluorescent protein (GFP). In the second, a signaling molecule known as AHL also turns on a gene that produces GFP. By measuring the total amount of GFP, the total amount of both inputs can be calculated.

To subtract or divide, the researchers swapped one of the activator transcription factors with a repressor, which turns off production of GFP when the input molecule is present. The team also built an analog square root circuit that requires just two parts, while a recently reported digital synthetic circuit for performing square roots had more than 100.

Network of cell mimics comes to life

Network of cell mimics comes to life: Built with a custom-made 3-D printer by scientists at the University of Oxford in England, the “droplet network” comprises tens of thousands of tiny water droplets connected by lipid layers...
To create the squishy, raftlike networks, the printer squirts a layer of water droplets into an oily solution. Lipids in the oil gather around microscopic water droplets like a cell’s membrane...

How to Make a Computer from a Living Cell

How to Make a Computer from a Living Cell: The Stanford researchers’ genetic logic gate can be used to perform the full complement of digital logic tasks, and it can store information, too. It works by making changes to the cell’s genome, creating a kind of transcript of the cell’s activities that can be read out later with a DNA sequencer...

The transcriptor triggers the production of enzymes that cause alterations in the cell’s genome. When the production of those enzymes is triggered by the signal—a protein of interest, for example—these enzymes will delete or invert a particular stretch of DNA in the genome. Researchers can code the transcriptor to respond to one, or multiple, different such signals. The signal can be amplified because one change in the cell’s DNA can lead the cell to produce a large amount of the output protein over time.

Wasp has hints of a clockwork brain

Wasp has hints of a clockwork brain: A tiny wasp has brain cells so small, physics predicts they shouldn't work at all. These miniature neurons might harbour subtle modifications, or they might work completely differently from all other known neurons - mechanically...
...Of 528 axons measured, a third were less than 0.1 micrometre in diameter, an order of magnitude narrower than human axons. The smallest were just 0.045 μm...
...That makes the axon impossibly noisy...
...The tiny axons might each carry a long rigid rod stretching down the centre. Pulling the rod could create a physical rather than electrical trigger for the release of a chemical that passes the signal on to the neighbouring neuron...

Artificial Jellyfish Swims Like the Real Thing

Artificial Jellyfish Swims Like the Real Thing: The duo and their colleagues stenciled out the ideal jellyfish shape on silicone, a material that would be sturdy but flexible, much like the jellyfish itself. They then coached rat muscle cells to grow in parallel bands on the silicone and encased the cells with a stretchy material called elastomer. To get their artificial jellyfish, or medusoid, swimming, the researchers submerged it in a salty solution and ran an electric current through the water, jump-starting the rat cells. The mimic propelled itself rapidly in the water, swimming as effectively as a real jellyfish, the researchers report online today in Nature Biotechnology.

A Big Magnet in a Small Fish - ScienceNOW

A Big Magnet in a Small Fish - ScienceNOW: Now, for the first time in any animal, scientists have isolated magnetic cells in the fish that respond to these fields...
The challenge in isolating magnetic cells is that they are few and far between—if they were clustered together they would interfere with each other's magnetism. "If you have a tissue containing these cells, it's likely that only one out of ten thousand cells is magnetic..."
To isolate magnetic cells from their non-magnetic neighbors, Winklhofer and his collaborators placed a suspension of rainbow trout (Oncorhynchus mykiss) cells under a microscope that had a magnet rotating around the stage that the sample sat on...
And surprisingly, the magnetism in each cell was tens to hundreds of times stronger than researchers had hypothesized, says Winklhofer...

Acoustic tweezers capture tiny creatures with ultrasound (w/ Video)

Acoustic tweezers capture tiny creatures with ultrasound (w/ Video): Acoustic tweezers use ultrasound, the same noninvasive technology doctors use to capture images of the fetus in the womb. The device is based on piezoelectric material that moves when under an electrical current. The vibrations pass through transducers attached to the piezoelectric substrate, where they are converted into standing surface acoustic waves (SAWs). The SAWs create pressure fields in the liquid medium that hold the specimen...
"We believe the device can be easily manufactured at a cost far lower than say, optical tweezers, which use lasers to manipulate single particles," said Tony Jun Huang, associate professor of bioengineering, whose group pioneered acoustic tweezers. "Optical tweezers require power densities 10,000,000 times greater than our acoustic tweezers, and the lasers can heat up and damage the cells, unlike ultrasound."

Biophoton Communication: Can Cells Talk Using Light? - Technology Review

Biophoton Communication: Can Cells Talk Using Light? - Technology Review: Mayburov has spent many hours in the dark watching fish eggs and recording the patterns of biophotons that these cells emit.
The question he aims to answer is whether the stream of photons has any discernible structure that would qualify it as a form of communication.
The answer is that is does, he says. Biophoton streams consist of short quasiperiodic bursts, which he says are remarkably similar to those used to send binary data over a noisy channel. That might help explain how cells can detect such low levels of radiation in a noisy environment...

In several experiments, biophotons from a growing plant seem to increase the rate of cell division in other plants by 30 per cent...
Other experiments have shown that the biophotons from growing eggs can encourage the growth of other eggs of a similar age.