UC Science Today

Scientists have developed a new deep learning technique that enables robots to learn motor tasks from scratch. Study leader Pieter Abbeel of the University of California, Berkeley says the robot learns based on a reward system, but is given no prior knowledge of its surroundings or how to complete the task, such as screwing a cap onto a bottle.

"If it's doing well, it gets a high reward. If it's doing poorly, it gets a low reward. And over time it figures out what behavior results in high rewards and what behavior results in low rewards. Let's say we want it to screw a cap onto a bottle. We would give it a high reward for bringing the cap very close to the top of the bottle, even higher reward when it's kind of placing it nicely onto the top of the bottle. And then, even higher if it's screwing the cap onto the bottle, and really low if it holds the cap very far away from the bottle."

Abbeel says it’s the first time a robot has learned a new task throughout the entire visual motor path, which takes about three hours of trial and error.

"We want robots to learn from their own trial and error, all the way from pixels coming into the camera to motor torques, so the entire visual motor path."

Why do researchers study astronomy if there’s not always a clear social benefit? Graduate student and planet hunter Lauren Weiss of the University of California, Berkeley says that other than satisfying curiosity, one reason is to someday travel to these planets and ensure our own survival.

"When I think about humanity, and the idea that we evolved from simple animals, to be curious and ask about the universe, and know that there are other planets out there, I think it would be really sad if our species came and went without ever leaving Earth. And that, to really be the next level of intelligent life form in civilization, we need to become space faring, and then that will also help ensure the survival of humanity over billions and billions of years. If we can spread ourselves out, instead of putting all our chips on one pale blue dot."

Weiss specializes in identifying exoplanets around nearby stars.

Why is it that some patients with Alzheimer’s disease can do complicated tasks like play the piano, but struggle to remember basic knowledge? While it’s unclear exactly why, scientists believe it has to do with toxins found in Alzheimer’s that target specific brain networks over others. Postdoctoral fellow Bryce Mander of the University of California, Berkeley explains.

"They target very specific brain networks. And the brain networks that are associated with promoting the how of how you do things, like how to ride a bike, how to hit a baseball with a bat, how to identify if a certain bird is a blue jay versus a crow. Those may not be as affected as much as the what, and the when and the who. Like who is this person? What do they do? When did you meet them? All that factual declarative knowledge gets deteriorated, but this procedural knowledge remains intact. And that's probably because very specific networks are affected and other networks aren't, and those other networks happen to support other abilities like procedural knowledge."

You've probably read or heard about scientists using radioactivity to determine the age of objects - most notably carbon-14 dating. We asked physicist Bruce Buchholz of the Lawrence Livermore National Laboratory to describe how it works.

"Carbon-14 is produced naturally in the atmosphere by cosmic ray interactions with molecules in the atmosphere. Some of the nitrogen-14 in the atmosphere gets converted to carbon-14 by nuclear reaction from the cosmic rays. That carbon-14 gets oxidized to carbon dioxide, which enters the food chain. So, everything that's alive has a level of carbon-14 naturally and that component of carbon-14 is used for traditional radiocarbon dating to measure how old things are after they die."

At the lab, Buchholz helped pioneer their Center for Accelerator Mass Spectrometry, or CAMS. It takes advantage of a dramatic increase in the atmospheric level of carbon-14 from aboveground nuclear testing in the late 50s and early 60s.

When California passed a bill in 2014 requiring labeling on upholstered furniture that contained toxic flame retardant chemicals, it was touted as a big win for human health and the environment. And it was no doubt especially meaningful to epidemiologist Brenda Ezkenazi of the University of California, Berkeley’s School of Public Health.

"Our work contributed heavily into new laws that were put into effect by our governor to restrict the use of these chemicals in the foam of our couches, in electronic products."

Eskenazi and her colleagues collected data from a study they began in 1999, which followed 600 mothers and their children to measure the impact on health from pesticides, chemicals in plastics and flame retardants.

"We’ve collected about a 150 thousand biological samples in this cohort and measured many different things in those samples. The relationship of flame retardants with neurodevelopment, relationships to fertility and many other health outcomes. So, our work has direct policy implications."

You’ve probably heard the Doppler effect – think of the change in pitch of an ambulance or horn as it passes by. This occurs when the frequency of a wave stretches or compresses as it moves relative to its source. It’s also a phenomenon that has helped astronomers like graduate student Lauren Weiss of the University of California, Berkeley to find planets around distant stars.

"So, this is true with light, as well as sound. So we are measuring the change in pitch of the light, as the star moves in space. And the reason that light changes its pitch, or frequency, is that there’s a planet orbiting the star and making the star wobble back and forth."

Weiss says that the Doppler technique is not new in astronomy, but her team has recently made new discoveries with the help of one using the Automated Planet Finder, which is a robotic telescope.

"It is one of the first times a robot has used the Doppler method to find planets around other stars."

Despite the rising prevalence of kidney stones in the U.S. over the past three decades, there hasn’t been much drug development to help prevent them. Dr. Thomas Chi of the University of California, San Francisco’s Department of Urology says while there haven’t been many successful treatment options, new surgical strategies have done amazingly well.

"It used to be that you'd have to have a giant open surgery, to open the kidney in order to get the stones out, and you'd lose a lot of kidneys that way, and a lot of blood loss. Nowadays, we have lots of minimally invasive options, most of those we specialize here at UCSF, and that includes shockwave therapy, small cameras that go into the kidney to use lasers to break up stones. And for really large stones, we can just make a small incision about a dime-size in your back, to go in and grind up stones. So the days of open surgery are pretty much over nowadays."

Chi is working to better understand how stones form, which he hopes will lead to new drug therapies in the future.

"So, we’re doing pretty good on the surgery front, but we really want to prevent people from getting stones in the first place."

As California faces its fourth year of record-breaking drought, many communities are finding ways to cut back to meet the state’s mandatory water use reductions. Ecology and Evolutionary Biology professor Peter Bowler of the University of California, Irvine says their campus has been doing its part by converting to drought-tolerant landscaping, or xeriscaping.

"The whole campus is going xeriscape. We’re deep into getting away from turf and using plants that preferably are native but at least use little water. We have a lot of drought-resistant vegetation. These plants become dormant during the dry seasons."

Bowler also directs the campus’s Aboretum, a facility for rare and native plant species. His team has had the challenge of balancing water reduction and preserving these endangered plants.

"We have an obligation to preserve and sustain these state-owned plants, but at the same time we’re doing our very best to keep water usage at an absolute minimum."

A good night’s rest could be the body’s best defense against the buildup of beta-amyloid, a toxic protein linked to Alzheimer’s disease. In a new study led by the University of California, Berkeley, researchers found that participants who had better quality sleep were able to retain more memories and had fewer deposits of beta-amyloid. Co-author Bryce Mander says that the findings add a preventative measure in a field where treatments have been largely unsuccessful.

"And one of the hypotheses from that is that well, amyloid has already ravaged the brain it's already triggered this degeneration. The neurons are already gone. So if you remove it, you know it's kind of like clearing the rubble after an earthquake, the damage has been done. But if you could do something before that maybe enhance the structural integrity of your roads or buildings so they don't break as much in an earthquake, the same for sleep. If you make the brain healthier, you promote the transformation of memories to be more permanent. You kind of help the structural integrity of the brain by enhancing sleep, then maybe the pathology would not be as successful at ravaging the brain."

Fruit flies have proven to be useful models to study kidney stones because they produce stones similar to those in humans. Using a fly model, a team of researchers led by urologist Dr. Thomas Chi of the University of California, San Francisco found that zinc plays a critical role in stone formation.

"So if we fed the fly zinc, they seem to increase their stone formation. If we reduce the amount of zinc inside their urine by either genetically knocking down their ability to transport zinc, or by giving them a drug that bound up all the zinc, their stone formation rates went down quite a lot, and so we think that without zinc present inside the kidney of the fly, stones are unable to form at the same rate."

Chi says that one of the goals is to prevent kidney stones from forming in the first place.

"We haven't had a new drug developed in the last twenty to twenty-five years. And so we're hoping that new research like this that looks at novel targets may open a window to develop new drugs."