Archive for the ‘Biotech’ Category
Robot controls a person’s arm using electrodes
Monday, November 21st, 2011A robot that can control both its own arm and a person’s arm to manipulate objects in a collaborative manner has been developed by Montpellier Laboratory of Informatics, Robotics, and Microelectronics (LIRMM) researchers, IEEE Spectrum Automation reports.
The robot controls the human limb by sending small electrical currents to electrodes taped to the person’s forearm and biceps, which allows the robot to command the elbow and hand to move. In the experiment, the person holds a ball, and the robot holds a hoop; the robot, a small humanoid, has to coordinate the movement of both human and robot arms to successfully drop the ball through the hoop.
The researchers say their goal is to develop robotic technologies that can help people suffering from paralysis and other disabilities to regain some of their motor skills.
Source | Kurzweil AI
Liquid Robotics’ Wave Gliders begin historic swim across Pacific
Monday, November 21st, 2011
Four Wave Gliders — self propelled robots, each about the size of a dolphin — left San Francisco on Nov. 17 for a 60,000 kilometer journey, IEEE Spectrum Automation reports.
Built by Liquid Robotics, the robots will use waves to power their propulsion systems and the Sun to power the sensors, as a capability demonstration. They will be measuring things like water salinity, temperature, clarity, and oxygen content; collecting weather data, and gathering information on wave features and currents.
The data from the fleet of robots is being streamed via the Iridium satellite network and made freely available on Google Earth’s Ocean Showcase.
Source | Kurzweil AI
Bidirectional brain signals sense and move virtual objects
Saturday, October 15th, 2011
In the study, monkeys moved and felt virtual objects using only their brain (credit: Duke University)
Two monkeys trained at the Duke University Center for Neuroengineering have learned to employ brain activity alone to move an avatar hand and identify the texture of virtual objects.
“Someday in the near future, quadriplegic patients will take advantage of this technology not only to move their arms and hands and to walk again, but also to sense the texture of objects placed in their hands, or experience the nuances of the terrain on which they stroll with the help of a wearable robotic exoskeleton,” said study leader Miguel Nicolelis, MD, PhD, professor of neurobiology at Duke University Medical Center and co-director of the Duke Center for Neuroengineering.
Sensing textures of virtual objects
Without moving any part of their real bodies, the monkeys used their electrical brain activity to direct the virtual hands of an avatar to the surface of virtual objects and differentiate their textures. Although the virtual objects employed in this study were visually identical, they were designed to have different artificial textures that could only be detected if the animals explored them with virtual hands controlled directly by their brain’s electrical activity.
The texture of the virtual objects was expressed as a pattern of electrical signals transmitted to the monkeys’ brains. Three different electrical patterns corresponded to each of three different object textures.
Because no part of the animal’s real body was involved in the operation of this brain-machine-brain interface, these experiments suggest that in the future, patients who were severely paralyzed due to a spinal cord lesion may take advantage of this technology to regain mobility and also to have their sense of touch restored, said Nicolelis.
First bidirectional link between brain and virtual body
“This is the first demonstration of a brain-machine-brain interface (BMBI) that establishes a direct, bidirectional link between a brain and a virtual body,” Nicolelis said.
“In this BMBI, the virtual body is controlled directly by the animal’s brain activity, while its virtual hand generates tactile feedback information that is signaled via direct electrical microstimulation of another region of the animal’s cortex. We hope that in the next few years this technology could help to restore a more autonomous life to many patients who are currently locked in without being able to move or experience any tactile sensation of the surrounding world,” Nicolelis said.
“This is also the first time we’ve observed a brain controlling a virtual arm that explores objects while the brain simultaneously receives electrical feedback signals that describe the fine texture of objects ‘touched’ by the monkey’s newly acquired virtual hand.
“Such an interaction between the brain and a virtual avatar was totally independent of the animal’s real body, because the animals did not move their real arms and hands, nor did they use their real skin to touch the objects and identify their texture. It’s almost like creating a new sensory channel through which the brain can resume processing information that cannot reach it anymore through the real body and peripheral nerves.”
The combined electrical activity of populations of 50 to 200 neurons in the monkey’s motor cortex controlled the steering of the avatar arm, while thousands of neurons in the primary tactile cortex were simultaneously receiving continuous electrical feedback from the virtual hand’s palm that let the monkey discriminate between objects, based on their texture alone.
Robotic exoskeleton for paralyzed patients
“The remarkable success with non-human primates is what makes us believe that humans could accomplish the same task much more easily in the near future,” Nicolelis said.
The findings provide further evidence that it may be possible to create a robotic exoskeleton that severely paralyzed patients could wear in order to explore and receive feedback from the outside world, Nicolelis said. The exoskeleton would be directly controlled by the patient’s voluntary brain activity to allow the patient to move autonomously. Simultaneously, sensors distributed across the exoskeleton would generate the type of tactile feedback needed for the patient’s brain to identify the texture, shape and temperature of objects, as well as many features of the surface upon which they walk.
This overall therapeutic approach is the one chosen by the Walk Again Project, an international, non-profit consortium, established by a team of Brazilian, American, Swiss, and German scientists, which aims at restoring full-body mobility to quadriplegic patients through a brain-machine-brain interface implemented in conjunction with a full-body robotic exoskeleton.
The international scientific team recently proposed to carry out its first public demonstration of such an autonomous exoskeleton during the opening game of the 2014 FIFA Soccer World Cup that will be held in Brazil.
Ref.: Joseph E. O’Doherty, Mikhail A. Lebedev, Peter J. Ifft, Katie Z. Zhuang, Solaiman Shokur, Hannes Bleuler, and Miguel A. L. Nicolelis, Active tactile exploration using a brain–machine–brain interface, Nature, October 2011 [doi:10.1038/nature10489]
Source | KurzweilAI
Brain linked to robotic hand; success hailed
Saturday, October 15th, 2011
Assistant professor Jennifer Collinger, left, watches as quadriplegic research subject Tim Hemmes operates the mechanical prosthetic arm in a testing session at UPMC. Read more: http://www.post-gazette.com/pg/11283/1181062-53.stm#ixzz1au8uO2qm
When it happened, emotions flashed like lightning.
The nearby robotic hand that Tim Hemmes was controlling with his mind touched his girlfriend Katie Schaffer’s outstretched hand.
One small touch for Mr. Hemmes; one giant reach for people with disabilities.
Tears of joy flowing in an Oakland laboratory that day continued later when Mr. Hemmes toasted his and University of Pittsburgh researchers’ success at a local restaurant with two daiquiris.
A simple act for most people proved to be a major advance in two decades of research that has proven to be the stuff of science fiction.
Mr. Hemmes’ success in putting the robotic hand in the waiting hand of Ms. Schaffer, 27, of Philadelphia, represented the first time a person with quadriplegia has used his mind to control a robotic arm so masterfully.
The 30-year-old man from Connoquenessing Township, Butler County, hadn’t moved his arms, hands or legs since a motorcycle accident seven years earlier. But Mr. Hemmes had practiced six hours a day, six days a week for nearly a month to move the arm with his mind.
That successful act increases hope for people with paralysis or loss of limbs that they can feed and dress themselves and open doors, among other tasks, with a mind-controlled robotic arm. It’s also improved the prospects of wiring around spinal cord injuries to allow motionless arms and legs to function once again.
“I think the potential here is incredible,” said Dr. Michael Boninger, director of UPMC’s Rehabilitation Institute and a principal investigator in the project. “This is a breakthrough for us.”
Mr. Hemmes? They say he’s a rock star.
In a project led by Andrew Schwartz, Ph.D., a University of Pittsburgh professor of neurobiology, researchers taught a monkey how to use a robotic arm mentally to feed itself marshmallows. Electrodes had been shallowly implanted in its brain to read signals from neurons known to control arm motion.
Electrocorticography or ECoG — in which an electronic grid is surgically placed against the brain without penetration — less intrusively captures brain signals.
ECoG has been used to locate sites of seizures and do other experiments in patients with epilepsy. Those experiments were prelude to seeking a candidate with quadriplegia to test ECoG’s capability to control a robotic arm developed by Johns Hopkins University.
The still unanswered question was whether the brains of people with long-term paralysis still produced signals to move their limbs.
ECoG picks up an array of brain signals, almost like a secret code or new language, that a computer algorithm can interpret and then move a robotic arm based on the person’s intentions. It’s a simple explanation for complex science.
Mr. Hemmes’ name cropped up so many times as a potential candidate that the team called him to gauge his interest.
He said no.
He already was involved in a research in Cleveland and feared this project would interfere. But knowing they had the ideal candidate, they called back. This time he agreed, as long as it would not limit his participation in future phases of research.
Mr. Hemmes became quadriplegic July 11, 2004, apparently after a deer darted onto the roadway, causing him to swerve his motorcycle onto gravel where his shoulder hit a mailbox, sending him flying headfirst into a guardrail. The top of his helmet became impaled on a guardrail I-beam, rendering his head motionless while his body continued flying, snapping his neck at the fourth cervical vertebra.
A passer-by found him with blue lips and no signs of breathing. Mr. Hemmes was flown by rescue helicopter to UPMC Mercy and diagnosed with quadriplegia — a condition in which he had lost use of his limbs and his body below the neck or shoulders. He had to learn how to breathe on his own. His doctor told him it was worst accident he’d ever seen in which the person survived.
But after the process of adapting psychologically to quadriplegia, Mr. Hemmes chose to pursue a full life, especially after he got a device to operate a computer and another to operate a wheelchair with head motions.
Since January, he has operated the website — www.Pittsburghpitbullrescue.com — to rescue homeless pit bulls and find them new owners.
The former hockey player’s competitive spirit and willingness to face risk were key attributes. Elizabeth Tyler-Kabara, the UPMC neurosurgeon who would install the ECoG in Mr. Hemmes’ brain, said he had strong motivation and a vision that paralysis could be cured.
Ever since his accident, Mr. Hemmes said, he’s had the goal of hugging his daughter Jaylei, now 8. This could be the first step.
“It’s an honor that they picked me, and I feel humbled,” Mr. Hemmes said.
Mr. Hemmes underwent several hours of surgery to install the ECoG at a precise location against the brain. Wires running under the skin down to a port near his collarbone — where wires can connect to the robotic arm — caused him a stiff neck for a few days.
Two days after surgery, he began exhaustive training on mentally maneuvering a computer cursor in various directions to reach and make targets disappear. Next he learned to move the cursor diagonally before working for hours to capture targets on a three-dimensional computer.
The U.S. Food and Drug Administration allowed the trial to last only 28 days, when the ECoG is removed. The project, initially funded by UPMC, has received more than $6 million in funding from the Department of Veterans Affairs, the National Institutes of Health, and the U.S. Department of Defense’s Defense Advanced Research Projects Agency, known as DARPA.
Initially Mr. Hemmes tried thinking about flexing his arm to move the cursor. But he had better success visually grabbing the ball-shaped cursor to throw it toward a target on the screen. The “mental eye-grabbing” worked best when he was relaxed.
Soon he was capturing 15 of 16 targets and sometimes all 16 during timed sessions. The next challenge was moving the robotic arm with his mind.
The same mental processes worked, but the arm moved more slowly and in real space. But time was ticking away as the experiment approached its final days last month. With Mr. Hemmes finally moving the arm in all directions, Wei Wang — assistant professor of physical medicine and rehabilitation at Pitt’s School of Medicine who also has worked on the signalling system — stood in front of him and raised his hand.
The robotic arm that Mr. Hemmes was controlling moved with fits and starts but in time reached Dr. Wang’s upheld hand. Mr. Hemmes gave him a high five.
The big moment arrived.
Katie Schaffer stood before her boyfriend with her hand extended. “Baby,” she said encouraging him, “touch my hand.”
It took several minutes, but he raised the robotic hand and pushed it toward Ms. Schaffer until its palm finally touched hers. Tears flowed.
“It’s the first time I’ve reached out to anybody in over seven years,” Mr. Hemmes said. “I wanted to touch Katie. I never got to do that before.”
“I have tattoos, and I’m a big, strong guy,” he said in retrospect. “So if I’m going to cry, I’m going to bawl my eyes out. It was pure emotion.”
Mr. Hemmes said his accomplishments represent a first step toward “a cure for paralysis.” The research team is cautious about such statements without denying the possibility. They prefer identifying the goal of restoring function in people with disabilities.
“This was way beyond what we expected,” Dr. Tyler-Kabara said. “We really hit a home run, and I’m thrilled.”
The next phase will include up to six people tested in another 30-day trial with ECoG. A year-long trial will test the electrode array that shallowly penetrates the brain. Goals during these phases include expanding the degrees of arm motions to allow people to “pick up a grape or grasp and turn a door knob,” Dr. Tyler-Kabara said.
Anyone interested in participating should call 1-800-533-8762.
Mr. Hemmes says he will participate in future research.
“This is something big, but I’m not done yet,” he said. “I want to hug my daughter.”
Carnegie Mellon competitions aimed at building useful robots
Sunday, September 18th, 2011Carnegie Mellon University will host a series of “RoboBowl“ competitions aimed at bringing new robotic technologies for manufacturing, healthcare, and national security applications, reports Network World.
Source | Kurzweil AI
‘Trojan horse’ particle sneaks chemotherapy in to kill ovarian cancer cells
Thursday, September 15th, 2011
Researchers at Queen Mary, University of London have delivered a common chemotherapy drug to cancer cells inside tiny microparticles. The drug reduced ovarian cancer tumors in an animal model by 65 times more than using the standard method. This approach is now being developed for clinical use.
The lead researcher Dr Ateh and colleagues found that by coating tiny microparticles of around 0.5 μm diameter with a special protein called CD95, they trigger cancer cells into ingesting these particles and deliver a dose of a common chemotherapy drug called paclitaxel.
The key to their success is that CD95 attaches to another protein called CD95L, which is found much more commonly on the surface of cancer cells than it is on normal healthy cells. Once attached, the cancer cells ingest CD95 and the microparticle with it. Inside the cell, the microparticle can unload its chemotherapy cargo, which kills the cell to reduce the size of the tumor.
The researchers are now advancing these studies and the start-up company BioMoti, which will develop the technology for clinical use, is planning to partner with established pharmaceutical companies for the clinical development of new treatments in specific types of cancer.
Ref.: Davidson D. Ateh et al., The intracellular uptake of CD95 modified paclitaxel-loaded poly(lactic-co-glycolic acid) microparticles, Biomaterials, August 2011
Source | KurzweilAI
Scientists copy the ways viruses deliver genes
Friday, August 12th, 2011National Physical Laboratory (NPL) scientists have mimicked the ways viruses infect human cells and deliver their genetic material, hoping to apply the approach to gene therapy to correct defective genes such as those that cause cancer.
The researchers used the GeT (gene transporter) model peptide sequence to transfer a synthetic gene encoding for a green fluorescent protein — a protein whose fluorescence in cells can be seen and monitored using fluorescence microscopy. GeT wraps around genes, transports them through cell membranes, and helps their escape from intracellular degradation traps. The process mimics the mechanisms viruses use to infect human cells.
GeT was designed to undergo differential membrane-induced folding — a process whereby the peptide changes its structure in response to only one type of membranes. This enables the peptide, and viruses, to carry genes into the cell. GeT is antibacterial and capable of gene transfer even in bacteria-challenged environments.
The gene transporter design can serve as a potential template for non-viral delivery systems and specialist treatments of genetic disorders, the researchers said.
Source | Kurzweil AI
Making biofuels 10 times faster
Friday, August 12th, 2011Engineering researchers at Rice University have developed a new method for rapidly converting simple glucose and mineral salts into biofuels and petrochemical substitutes.
The team has reversed the beta oxidation cycle to engineer bacteria that produce the biofuel butanol about 10 times faster than any previously reported organism.
The team reversed the beta oxidation cycle by selectively manipulating about a dozen genes in the bacteriaEscherichia coli. They also showed that selective manipulations of particular genes could be used to produce fatty acids of particular lengths, including long-chain molecules like stearic acid and palmitic acid, which have chains of more than a dozen carbon atoms.
This process can make many kinds of specialized molecules for many different markets — using almost any organism (algae or yeast, for example), the researchers said.
Source | Kurzweil AI
Genetically engineered spider silk improve gene therapy
Friday, August 12th, 2011Genetically engineered spider silk could help overcome a major barrier to the use of gene therapy in everyday medicine — the lack of safe and efficient carriers or “vectors,” Tufts University scientists have found.

Human breast cancer cells growing in lab mice. The fluorescent signals indicate that a gene has successfully reached its target
The lack of good gene delivery systems is a main reason why there are no FDA-approved gene therapies, despite almost 1,500 clinical trials since 1989.
They modified spider silk proteins so that the proteins were able to attach to cancer cells, and they used mice containing human breast-cancer cells. The spider-silk proteins attached to the cancer cells and transported the DNA material into the cells — without harming the mice.
To provide a visual signal that the gene reached its intended target, they also engineered the spider silk to contain a gene that codes for the protein that makes fireflies glow.
The results suggest that the genetically engineered spider-silk proteins represent “a versatile and useful new platform polymer for nonviral gene delivery,” the researchers said.
Source | Kurzweil AI
First direct biological evidence found for genetic contribution to intelligence
Wednesday, August 10th, 2011Scientists at The University of Edinburgh, U.K., have found.the first direct biological evidence for a genetic contribution to people’s intelligence.
The team studied two types of intelligence in more than 3,500 people from Scotland, England and Norway. They found that 40 to 50 percent of people’s differences in knowledge and problem solving skills could be traced to their genes. The study examined more than half a million genetic markers on every person’s DNA.
Previous studies on twins and adopted people suggested that there is a substantial genetic contribution to thinking skills. However, the new study is the first to test people’s DNA for genetic variations linked to intelligence.
Technical details of the study
The researchers conducted a genome-wide association study looking at over 500,000 common single nucleotide polymorphisms (SNPs), which are DNA sequence variations that occur when a single nucleotide (A,T,C,or G) in the genome sequence is altered. They correlated genetic variation of participants’ performance on two types of general intelligence: knowledge and problem-solving skills.
The researchers found that up to half of individual differences in intelligence are due to genetic variants in linkage disequilibrium with SNPs. (Individuals often inherit rather long haplotypes (chunks) of DNA from one parent or the other, and some haplotypes themselves may also be inherited as a group. This is called linkage disequilibrium.)
The researchers found that a large proportion of the heritability estimate of intelligence in adulthood can be traced to genetic variants linked with common SNPs, confirming that at least 40–50% of individual differences in human intelligence are due to genetic variation.
The findings were made possible using a new type of analysis invented by Professor Peter Visscher and colleagues in the Queensland Institute of Medical Research, Brisbane.
Source | Kurzweil AI
NASA research shows DNA building blocks can be made in space
Tuesday, August 9th, 2011Scientists at GNASA’s Goddard Space Flight Center have foundtrace amounts of three molecules related to DNA nucleobases adenine and guanine in samples of 12 carbon-rich meteorites, nine of which were recovered from Antarctica.
These nucleobase-related molecules, called nucleobase analogs, provide the first evidence that the compounds in the meteorites came from space and not terrestrial contamination.
The team analyzed an eight-kilogram (21.4-pound) sample of ice from Antarctica, where most of the meteorites in the study were found. The amounts of nucleobases found in the ice were much lower than in the meteorites.

NASA-funded researchers have found more evidence meteorites can carry DNA components created in space
More significantly, none of the nucleobase analogs were detected in the ice sample. The team also analyzed a soil sample collected near one of the non-Antarctic meteorite’s fall site. As with the ice sample, the soil sample had none of the nucleobase analog molecules present in the meteorite.
Source | Kurzweil AI
Human skin cells converted directly into functional neurons
Tuesday, August 9th, 2011Researchers at Columbia University Medical Center have directly converted human skin cells into functional forebrain neurons, without the need for stem cells of any kind.

Schematic of the conversion from adult skin fibroblasts to human-induced neuronal cells. Top panels show phase contrast images of human skin fibroblast (left) or hiN cell (right) cultures.
The researchers used a combination of transcription regulators, plus several neuronal support factors, to convert human skin cells into forebrain neurons. This bypassed the need for induced pluripotent stem (iPS) cells. The induced neurons appear to be the same as ordinary neurons, judging from electrophysiological testing and gene expression profiling. The researchers also showed that the neurons are able to send and receive signals in laboratory culture and when transplanted into the central nervous system of mice.
The researchers compared neurons made from skin cells of healthy individuals with neurons made from patients with early-onset Alzheimer’s disease. The latter cells exhibited altered processing and localization of amyloid precursor protein (APP) and increased concentration of amyloid beta, a component of APP (Alzheimer’s is thought to develop when abnormal amounts of amyloid beta accumulate in the brain, eventually killing neurons). APP was found to collect in the cells’ endosomes, cellular compartments that sort molecules for degradation or recycling. These findings suggest that this form of Alzheimer’s is caused, at least in part, by abnormal endosomal function, the researchers said.
The findings offer a new and potentially more direct way to produce replacement cell therapies for Alzheimer’s and other neurodegenerative diseases.
Source | Kurzweil AI
2011 State of the Future
Monday, August 1st, 2011The Millennium Project’s 2011 State of the Future Report, due out August 1, finds that while people are getting richer, healthier, better educated, and living longer, and the world is more peaceful and better connected, half of the world is potentially unstable.
“Food prices are rising, water tables are falling, corruption and organized crime is increasing, environmental viability for life support is diminishing, debt and economic insecurity are increasing, climate change continues, and the gap between the rich and poor is widening dangerously,” the report says. “People voting in elections, corruption, people killed or injured in terrorist attacks, and refugees and displaced persons are also identified as key problems.
“The world is in a race between implementing ever-increasing ways to improve the human condition and the seemingly ever-increasing complexity and scale of global problems.”
The 2011 State of the Future is an overview of our global situation, problems, solutions, and prospects for the future. “15 Global Challenges” including energy, food, science and technology, ethics, development, water, organized crime, health, decision-making, gender relations, demographics, war and peace, and others are analyzed, studied, and recommendations are made.

Where we are winning. An international Delphi panel selected more than 100 indicators of progress or regress for the 15 Global Challenges. Indicators were then chosen that had at least 20 years of reliable historical data and later, where possible, were matched with variables used in the International Futures model. The resulting 28 variables were integrated into the State of the Future Index with a 10-year projection.
This report discusses a broad range of future-oriented policy initiatives, such as shifting from fresh water-based agriculture to saltwater-based agriculture; making environmental security the focus of US-China strategic trust, a global strategy to counter organized crime, and collective intelligence as one of the next big topics of interest.
It also alerts readers to major changes that seem inevitable. For example, the coming biological revolution may change civilization more profoundly than did the industrial or information revolutions. The world has not come to grips with the implications of writing genetic code to create new lifeforms. Thirteen years ago, the concept of being dependent on Google searches was unknown to the world; today we consider it quite normal. Thirteen years from today, the concept of being dependent on synthetic life forms for medicine, food, water, and energy could also be quite normal.
The 2011 State of the Future comes in two parts: a print 106-page distillation of research with tables, graphs, and charts, and an 8,500-page CD. comes in two parts: a print 106-page distillation of research with tables, graphs, and charts, and an 8,500-page CD. Price: $49.95 US dollars plus shipping.
The Millennium Project was established in 1996 as the first globalized think tank. It conducts independent futures research via its 40 Nodes around the world that connect global and local perspectives.
Source | Kurzweil AI
New tools accelerate mapping the brain’s connectome
Friday, July 29th, 2011New software tools to reconstruct neural wiring diagrams quickly and accurately have been developed by researchers at the Max Planck Institute for Medical Research to allow neuroscientists to understand the structure of the brain’s circuits — the connectome.

A reconstruction of 114 rod bipolar nerve cells from a piece of mouse retina. The dense bundles (top) are dendrites, and the sparser processes below are axons
The researchers created two new computer programs, KNOSSOS (named for Crete’s legendary palace, renowned for its elaborate labyrinth) and RESCOP, and mapped a network of 114 neurons from a mouse retina faster and more accurately than with previous methods.
The researchers started by staining the neurons of a section of tissue with heavy metals to make them visible. Using three-dimensional electron microscope images, they started at the cell body and followed the dendrites and axons, marking the branch point nodes on the screen. Then they used a computer to generate a three-dimensional image of the section.
The KNOSSOS software is about 50 times faster than other programs in tracing connections between neurons. The RESCOP program allows dozens of people to work on the reconstruction at the same time and allows for error detection and reduction.
With some 70 billion neurons, each neuron linked to about a thousand others via dendrites and axons, and hundreds of thousands of kilometers of circuits, the human brain is so complex that for many years, it seemed impossible to reconstruct the network in detail, the researchers said.

Dendrites form dense bundles where bipolar cells receive signals from rod photoreceptors (gray spheres)
One person working alone with the currently available programs would take at least 30 years to reconstruct a path of just 30 centimeters in length, they estimate. Besides, these procedures are prone to error, since the branch points are not always easily recognized and the annotator’s attentiveness decreases with time.
Source | Kurzweil AI


