The university occupies 2,141 acres (866 ha) near the coast of the Pacific Ocean with the main campus resting on approximately 1,152 acres (466 ha). Established in 1960 near the pre-existing Scripps Institution of Oceanography, UCSD is the seventh oldest of the 10 University of California campuses and offers over 200 undergraduate and graduate degree programs, enrolling about 22,700 undergraduate and 6,300 graduate students. UCSD is one of America’s Public Ivy universities, which recognizes top public research universities in the United States. UC San Diego was ranked 39th among the top universities in the United States, tied for 3rd with UC Davis of the University of California schools, and 9th among public universities by U.S. News & World Report ‘s 2014 rankings.
UC San Diego is organized into six undergraduate residential colleges, five graduate schools, and two professional medical schools. The university operates four research institutes, including the California Institute for Telecommunications and Information Technology, San Diego Supercomputer Center, Scripps Institution of Oceanography, and UC San Diego Health System, and is also affiliated with several regional research centers, such as the Salk Institute, the Sanford-Burnham Medical Research Institute, the Sanford Consortium for Regenerative Medicine, and the Scripps Research Institute. The university also houses two think tanks, the Institute on Global Conflict and Cooperation and Center for Comparative Immigration Studies. UC San Diego faculty, researchers, and alumni have won twenty Nobel Prizes, eight National Medals of Science, eight MacArthur Fellowships, two Pulitzer Prizes, and two Fields Medals. Additionally, of the current faculty, 29 have been elected to the National Academy of Engineering, 95 to the National Academy of Sciences, and 106 to the American Academy of Arts and Sciences.
University of California, San Diego research articles from Innovation Toronto
- ‘Adaptive Protein Crystal’ Could Form New Kind of Protective Material – May 3, 2016
- New Metallic Glass Bounces and Could Protect – April 5, 2016
- ‘Stunning’ operation regenerates eye’s lens – March 9, 2016
- Biologists Develop Method for Antibiotic Susceptibility Testing – January 24, 2016
- Noise can’t hide weak signals from this new receiver – December 13, 2015
- Electric fields remove nanoparticles from blood with ease – November 24, 2015
- Tiny carbon-capturing motors may help tackle rising carbon dioxide levels – September 25, 2015
- Researchers unveiled cloaking technology that the US military has been waiting for – September 23, 2015
- Hearts build new muscle with this simple protein patch – September 21, 2015
- These microscopic fish are 3D-printed to do more than swim – August 26, 2015
- 3D-printed Robot is Hard at Heart, Soft on Outside – July 10, 2015
- An Advance May Double the Capabilities of Fiber Optics – June 26, 2015
- Scientists Create Synthetic Membranes That Grow Like Living Cells – June 25, 2015
- Pens filled with high-tech inks for Do It Yourself sensors – March 4, 2015
- Telescopic contact lenses and wink-control glasses – February 16, 2015
- Nanobot micromotors deliver medical payload in living creature for the first time – January 26, 2015
- ‘Nanomotor lithography’ answers call for affordable, simpler device manufacturing – November 2, 2014
- New solar power material converts 90 percent of captured light into heat – October 31, 2014
- UC San Diego Researchers Build First 500 GHz Photon Switch – September 14, 2014
- Ultrasonically propelled nanorods spin at 150,000 rpm! – July 28, 2014
- Computer scientists develop tool to make the Internet of Things safer – June 18, 2014
- How to Erase a Memory – And Restore It – June 2, 2014
- Bioprinting a 3D Liver-Like Device to Detoxify the Blood | biofabrication – May 15, 2014
- Nanoengineers Develop Basis for Electronics That Stretch at the Molecular Level | stretchable electronics – May 8, 2014
- Engineers develop new materials for hydrogen storage – April 18, 2014
- Good Vibrations: Using Light-Heated Water to Deliver Drugs
- Material Could Speed Up Underwater Communications by Orders of Magnitude
- Robotic Surgery Program Expands at UC San Diego Health System to Treat Stomach Cancer
- UC San Diego Computer Scientists Develop First-person Player Video Game that Teaches How to Program in Java
- Scripps Oceanography Researchers Engineer Breakthrough for Biofuel Production
- UCSD students test fire 3D-printed metal rocket engine
- From slowdown to shutdown — US leadership in biomedical research takes a blow, says ASCB
- Biologists Discover New Method for Discovering Antibiotics
- Chemists develop new approaches to understanding disturbing trends near Earth’s surface
- Touch Goes Digital
- New Electron Beam Writer Enables Next-Gen Biomedical and Information Technologies
- SkySweeper Robot Makes Inspecting Power Lines Simple and Inexpensive
- Disappearance of Coral Reefs, Drastically Altered Marine Food Web on the Horizon
- Natural pest control protein effective against hookworm: A billion could benefit
- Studies Suggest New Key to “Switching Off” Hypertension
- Telescopic Contact Lens Could Improve Eyesight for the Visually Impaired
- A Telescope For Your Eye: New Contact Lens Design May Improve Sight of Patients with Macular Degeneration
- Firefighting Robot Paints 3D Thermal Imaging Picture for Rescuers
- Shape-shifting Nanoparticles Flip from Sphere to Net in Response to Tumor Signal
- Whirlpools on the Nanoscale Could Multiply Magnetic Memory
- Seahorse’s Armor Gives Engineers Insight Into Robotics Designs
- New Plant Protein Discoveries Could Ease Global Food and Fuel Demands
- Quest for Edible Malarial Vaccine Leads to Other Potential Medical Uses for Algae
- Nanosponges soak up toxins released by bacterial infections and venom
- Overcoming a major barrier to medical and other uses of ‘microrockets’ and ‘micromotors’
- Are Algae Biofuels a Realistic Alternative to Petroleum?
- New Breakthrough Prize Awards Millions to Life Scientists
- Small, Portable Sensors Allow Users to Monitor Exposure to Pollution on Their Smart Phones
- Biologists Engineer Algae to Make Complex Anti-Cancer ‘Designer’ Drug
- Medical Devices Powered by the Ear Itself
- If You Had A Microgrid, You Wouldn’t Be Waiting For The Power Company
- New Sophisticated Control Algorithms Poised to Revolutionize Electric Battery Technology
- Nanoengineers can print 3D microstructures in mere seconds
- Megapixel Camera? Try Gigapixel
- Self-Assembling Nanocubes for Next Generation Antennas and Lenses
- Research Unveils Drug Against Entamoeba Hisotolica
- Biologists Produce Potential Malarial Vaccine from Algae
- Researchers Make Breakthrough in Treating Lou Gehrig’s Disease
- A Little Device That’s Trying to Read Your Thoughts
- Solar energy-harvesting “nanotrees” could produce hydrogen fuel on a mass scale
- Hydrogel could grow new heart tissue, without the need for surgery
- New ‘Biopsy in a Blood Test’ to Detect Cancer
- Wireless Sensors Monitor Brain Waves on the Fly
- How to Buy Time in the Fight against Climate Change
- New “smart” polymer opens door for medical use of low-power near-infrared light
- New Way to Target – And Kill – Proliferating Tumors
- Coming to TV Screens of the Future: A Sense of Smell
- Cyber Attack Risk on Car Computers
- New Material Could Improve Safety for First Responders to Chemical Hazards
- Your Most Vital Lesson
- Getting Computers to Understand Overlapping Speech
- Computer Scientists Take Over Electronic Voting Machine With New Programming Technique
- Bioengineers achieve holy trinity of stem cell culture
- Heads-Up Virtual Reality device lets users see and ‘touch’ 3D images
- Enterprise PCs Work While They Sleep – Saving Energy and Money – With New Software
- The Idea Incubator Goes to Campus
- Solar Energy: Cheaper Solar Concentrator With Fewer Photovoltaic Cells
- First robotic underwater vehicle to be powered entirely by natural, renewable, ocean thermal energy
- Using The Weather To Go Green
- Innovation through regulation
- New study offers hope for halting incurable citrus disease
- Novel sensor provides bigger picture
- Invisibility Cloaking to Shield Floating Objects from Waves
- Cancer cells poisoned with sugar
- Long-Lived Fruit Flies Offer Clues to Slowing Human Aging and Fighting Disease
- Smart Skin: Electronics That Stick and Stretch Like a Temporary Tattoo
- Secreting Bacteria Eliminate Cost Barriers for Renewable Biofuel Production
- ‘M8′ Earthquake Simulation Breaks Computational Records, Promises Better Quake Models
- Automobile computer systems successfully hacked
- Hack attacks mounted on car control systems
- Tiny Sensors In Cell Phones Could Map Airborne Toxins in Real Time
- The (good and bad) future of the Internet
- Plugging Highway Vehicles into the Electric Grid
Researchers at the University of California San Diego have demonstrated the world’s first laser based on an unconventional wave physics phenomenon called bound states in the continuum. The technology could revolutionize the development of surface lasers, making them more compact and energy-efficient for communications and computing applications.
The new BIC lasers could also be developed as high-power lasers for industrial and defense applications.
“Lasers are ubiquitous in the present day world, from simple everyday laser pointers to complex laser interferometers used to detect gravitational waves. Our current research will impact many areas of laser applications,” said Ashok Kodigala, an electrical engineering Ph.D. student at UC San Diego and first author of the study.
“Because they are unconventional, BIC lasers offer unique and unprecedented properties that haven’t yet been realized with existing laser technologies,” said Boubacar Kanté, electrical engineering professor at the UC San Diego Jacobs School of Engineering who led the research.
For example, BIC lasers can be readily tuned to emit beams of different wavelengths, a useful feature for medical lasers made to precisely target cancer cells without damaging normal tissue. BIC lasers can also be made to emit beams with specially engineered shapes (spiral, donut or bell curve) — called vector beams — which could enable increasingly powerful computers and optical communication systems that can carry up to 10 times more information than existing ones.
“Light sources are key components of optical data communications technology in cell phones, computers and astronomy, for example. In this work, we present a new kind of light source that is more efficient than what’s available today in terms of power consumption and speed,” said Babak Bahari, an electrical engineering Ph.D. student in Kanté’s lab and a co-author of the study.
Bound states in the continuum (BICs) are phenomena that have been predicted to exist since 1929. BICs are waves that remain perfectly confined, or bound, in an open system. Conventional waves in an open system escape, but BICs defy this norm — they stay localized and do not escape despite having open pathways to do so.
In a previous study, Kanté and his team demonstrated, at microwave frequencies, that BICs could be used to efficiently trap and store light to enable strong light-matter interaction. Now, they’re harnessing BICs to demonstrate new types of lasers. The team published the work Jan. 12 in Nature.
Controls engineers at UC San Diego have developed practical strategies for building and coordinating scores of sensor-laden balloons within hurricanes.
Using onboard GPS and cellphone-grade sensors, each drifting balloon becomes part of a “swarm’’ of robotic vehicles, which can periodically report, via satellite uplink, their position, the local temperature, pressure, humidity and wind velocity.
This new, comparatively low-cost sensing strategy promises to provide much-needed in situ sampling of environmental conditions for a longer range of time and from many vantage points within developing hurricanes. This has the potential to greatly improve efforts to estimate and forecast the intensity and track of future hurricanes in real time.
Current two to five day forecasts of many hurricanes deviate significantly from each other, and from the truth. For example, as Hurricane Matthew churned toward the eastern seaboard in early October of 2016, various news outlets reported “forecasts” like “Hurricane Matthew will probably make landfall somewhere between Charleston and Boston, so everyone brace yourselves.”
“Guidance like this is entirely inadequate for evacuation and emergence response preparations,” said Thomas Bewley, a professor at the Jacobs School of Engineering at UC San Diego and the paper’s senior author.
Improved forecasts, to be greatly facilitated by improved in situ environmental sampling, are essential to protect property and save lives from such extreme environmental threats, he added.
Key challenges in this effort include the design of small, robust, buoyancy-controlled balloons that won’t accumulate ice; the efficient coordination of the motion of these balloons to keep them moving within the hurricane, between an altitude of 0 and 8 kilometers (about 5 miles); and to keep them well distributed over the dynamically significant regions within the hurricane, for up to a week at a time.
Bewley and UC San Diego post-doctoral researcher Gianluca Meneghello detail various aspects of their work on this problem in the October 2016 issue of the Physical Review Fluids, building upon work they published in the proceedings of the eighth International Symposium on Stratified Flows (ISSF) in San Diego, (Sept. 1, 2016). They plan to expand on their work at the forthcoming IEEE Aerospace Conference in Big Sky, Mont. (March 6, 2017).
|Typical spread of the zero- to five-day forecasts of the track of Hurricane Matthew, as performed by the major hurricane forecasting centers on (left) Oct 3, (middle) Oct 6, and (right) Oct 7, 2016.|
Data from http://www.emc.ncep.noaa.gov/gc_wmb/vxt/HWRF/tcall.php?selectYear=2016&selectBasin=North+Atlantic&selectStorm=MATTHEW14L
How the model works
The model for large-scale coordination of balloon swarms within hurricanes, as discussed in the Physical Review Fluids article, uses a clever strategy to model predictive control by leveraging the cutting-edge Weather Research and Forecasting code developed by the National Center for Atmospheric Research, the National Oceanic and Atmospheric Administration and the Air Force Weather Agency (AFWA). Multiple simulations indicate the remarkable effectiveness of this approach, including a simulation based on the evolution of Hurricane Katrina as it moved across the Gulf of Mexico, as summarized in the video available at http://flowcontrol.ucsd.edu/katrina.mp4
`The key idea of our large-scale balloon coordination strategy,’’ said Bewley, “is to `go with the flow,’ commanding small vertical movements of the balloons and leveraging the strong vertical stratification of the horizontal winds within the hurricane to distribute the balloons in the desired fashion horizontally.”
Intermediate-scale and small-scale fluctuations in the violent turbulent flow of a hurricane, which are unresolved by forecasting codes like WRF, are quite substantial. The researchers’ strategy? “We simply ride out the smaller-scale fluctuations of the flow,” said Meneghello. “The smaller-scale flowfield fluctuations induce something of a random walk in the balloon motion. We model these fluctuations statistically, and respond with corrections only if a balloon deviates too far from its desired location in the formation.”
Background on the project
As summarized in their ISSF paper, the researchers’ strategy for applying such corrections, dubbed Three Level Control (and endearingly abbreviated TLC), applies a finite shift to the vertical location of the displaced balloon for a short period of time, again leveraging the strong vertical stratification of the horizontal winds to return the balloon to its nominal desired location.
A third essential ingredient of the project, summarized in the researchers’ IEEE paper, is the design of small (about 3 kg or 6.5 lbs.), robust, energetically-efficient, buoyancy-controlled balloons that can survive, without significant accumulation of ice, in the cold, wet, turbulent, electrically active environment of a hurricane. The balloons can operate effectively for up to a week at a time on a battery charge not much larger than that of a handful of iPhones. “Cellphone-grade technologies, for both environmental sensors as well as low-energy radios and microprocessors, coupled with new space-grade balloon technology developed by Thin Red Line Aerospace, are on the cusp of making this ambitious robotic sensing mission feasible,” said Bewley.
Control theory applied
In addition to robotics, Bewley’s team specializes in the field of control theory, which is the essential “hidden technology” in many engineering applications, such as cruise control and adaptive suspension systems in cars, stability augmentation systems in high-performance aircraft and adaptive noise cancellation in telecommunication. Control theory made it possible for SpaceX rockets to land on barges at sea.
Though the math and numerical methods involved are sophisticated, the fundamental principle is straightforward: sensors take measurements of the physical environment, then a computer uses these measurements in real time to coordinate appropriate responses by the system (in this case, the buoyancy of the balloons) to achieve the desired effect.
Bewley, Meneghello and colleagues are now working towards testing the balloons and algorithms designed in this study in the real world. With sensor balloon swarms and the special TLC coming out of their lab, fire and safety officials may soon have a crucial extra couple of days to move people out of harm’s way, and to prepare emergency responses, when the next Katrina or Sandy threatens.
Biologists have discovered that the evolution of a new species can occur rapidly enough for them to observe the process in a simple laboratory flask.
In a month-long experiment using a virus harmless to humans, biologists working at the University of California San Diego and at Michigan State University documented the evolution of a virus into two incipient species—a process known as speciation that Charles Darwin proposed to explain the branching in the tree of life, where one species splits into two distinct species during evolution.
“Many theories have been proposed to explain speciation, and they have been tested through analyzing the characteristics of fossils, genomes, and natural populations of plants and animals,” said Justin Meyer, an assistant professor of biology at UC San Diego and the first author of a study that will be published in the December 9 issue of Science.“However, speciation has been notoriously difficult to thoroughly investigate because it happens too slowly to directly observe. Without direct evidence for speciation, some people have doubted the importance of evolution and Darwin’s theory of natural selection.”
Meyer’s study, which also appeared last week in an early online edition of Science, began while he was a doctoral student at Michigan State University, working in the laboratory of Richard Lenski, a professor of microbial ecology there who pioneered the use of microorganisms to study the dynamics of long-term evolution.
“Even though we set out to study speciation in the lab, I was surprised it happened so fast,” said Lenski, a co-author of the study. “Yet the deeper Justin dug into things—from how the viruses infected different hosts to their DNA sequences—the stronger the evidence became that we really were seeing the early stages of speciation.”
“With these experiments, no one can doubt whether speciation occurs,” Meyer added. “More importantly, we now have an experimental system to test many previously untestable ideas about the process.”
To conduct their experiment, Meyer, Lenski and their colleagues cultured a virus—known as “bacteriophage lambda”—capable of infecting E. coli bacteria using two receptors, molecules on the outside of the cell wall that viruses use to attach themselves and then infect cells.
When the biologists supplied the virus with two types of cells that varied in their receptors, the virus evolved into two new species, one specialized on each receptor type.
“The virus we started the experiment with, the one with the nondiscriminatory appetite, went extinct. During the process of speciation, it was replaced by its more evolved descendants with a more refined palette,” explained Meyer.
Why did the new viruses take over?
“The answer is as simple as the old expression, ‘a jack of all trades is a master of none’,” explained Meyer. “The specialized viruses were much better at infecting through their preferred receptor and blocked their ‘jack of all trades’ ancestor from infecting cells and reproducing. The survival of the fittest led to the emergence of two new specialized viruses.”
Researchers from the University of California San Diego have developed a novel design for a compact, ultra-sensitive nanosensor that can be used to make portable health-monitoring devices and to detect minute quantities of toxins and explosives for security applications.
The study addresses one of the major challenges of nanosensor design: how to increase sensitivity while reducing size.
The nanosensor design presented in this study combines three-dimensional plasmonic nanoparticles with singularities called exceptional points—a combination that’s being demonstrated for the first time. “The new physics implemented here could potentially outcompete the plasmonic technologies currently in use for sensing,” said Boubacar Kanté, electrical engineering professor at the UC San Diego Jacobs School of Engineering and senior author of the study. Kanté and his team published their novel design Nov. 8 online in the rapid communication section of the journal Physical Review B.
Singularities, such as exceptional points, are fundamental in physics due to their uncanny ability to induce a large response from a small excitation, Kanté explained. Singularities occur when a quantity is undefined or infinite, such as the density at the center of black hole, for example. Exceptional points occur when two waves become degenerate, meaning that both their resonant frequencies and spatial structure merge as one.
“Exceptional points have been highly sought after for sensors and enhanced light-matter interactions,” said Ashok Kodigala, a PhD student in Kanté’s lab and first author of the study. “The possibility to demonstrate exceptional points in systems that are simultaneously sub-wavelength and compatible with small biological molecules for sensing has remained elusive—until now.”
Nanosensors operate based on a phenomenon called frequency splitting, meaning that the presence of a substance perturbs the degeneracy between two resonant frequencies and causes a detectable split. In an exceptional-point-based nanosensor, resonant frequencies would split much faster than they do in traditional nanosensors, giving rise to enhanced detection capabilities.
By combining exceptional points and plasmonics, researchers formulated a design for a nanosensor that is both compact and ultra-sensitive.
“We believed that designing such a nanosensor requires not just a gradual improvement of existing devices, but a conceptual breakthrough. That is why we chose to focus on exceptional-point-based-nanosensors,” Kodigala said.
In this study, researchers proposed what Kodigala calls “a general recipe to obtain exceptional points on demand.” The method involves controlling the interaction between symmetry-compatible modes of the plasmonic system.
The nanosensor design has only been demonstrated computationally so far. The team is working on integrating the exceptional-point-based nanosensors on a chip.
“Once we optimize some of the main parameters of this system to minimize ohmic and radiative losses, we can start transitioning this research from the theoretical stage to a commercially relevant product,” Kanté said. The team has filed a patent on the technology.
A team of mechanical engineers at the University of California San Diego has successfully used acoustic waves to move fluids through small channels at the nanoscale. The breakthrough is a first step toward the manufacturing of small, portable devices that could be used for drug discovery and microrobotics applications. The devices could be integrated in a lab on a chip to sort cells, move liquids, manipulate particles and sense other biological components. For example, it could be used to filter a wide range of particles, such as bacteria, to conduct rapid diagnosis.
The researchers detail their findings in the Nov. 14 issue of Advanced Functional Materials. This is the first time that surface acoustic waves have been used at the nanoscale.
The field of nanofluidics has long struggled with moving fluids within channels that are 1000 times smaller than the width of a hair, said James Friend, a professor and materials science expert at the Jacobs School of Engineering at UC San Diego. Current methods require bulky and expensive equipment as well as high temperatures. Moving fluid out of a channel that’s just a few nanometers high requires pressures of 1 megaPascal, or the equivalent of 10 atmospheres.
Researchers led by Friend had tried to use acoustic waves to move the fluids along at the nano scale for several years. They also wanted to do this with a device that could be manufactured at room temperature.
After a year of experimenting, post-doctoral researcher Morteza Miansari, now at Stanford, was able to build a device made of lithium niobate with nanoscale channels where fluids can be moved by surface acoustic waves. This was made possible by a new method Miansari developed to bond the material to itself at room temperature. The fabrication method can be easily scaled up, which would lower manufacturing costs. Building one device would cost $1000 but building 100,000 would drive the price down to $1 each.
The device is compatible with biological materials, cells and molecules.
Researchers used acoustic waves with a frequency of 20 megaHertz to manipulate fluids, droplets and particles in nanoslits that are 50 to 250 nanometers tall. To fill the channels, researchers applied the acoustic waves in the same direction as the fluid moving into the channels. To drain the channels, the sound waves were applied in the opposite direction.
By changing the height of the channels, the device could be used to filter a wide range of particles, down to large biomolecules such as siRNA, which would not fit in the slits. Essentially, the acoustic waves would drive fluids containing the particles into these channels. But while the fluid would go through, the particles would be left behind and form a dry mass. This could be used for rapid diagnosis in the field.
A team of engineers at the University of California San Diego has developed a magnetic ink that can be used to make self-healing batteries, electrochemical sensors and wearable, textile-based electrical circuits.
The key ingredient for the ink is microparticles oriented in a certain configuration by a magnetic field. Because of the way they’re oriented, particles on both sides of a tear are magnetically attracted to one another, causing a device printed with the ink to heal itself. The devices repair tears as wide as 3 millimeters—a record in the field of self-healing systems.
Researchers detail their findings in the Nov. 2 issue of Science Advances.
“Our work holds considerable promise for widespread practical applications for long-lasting printed electronic devices,” said Joseph Wang, director of the Center for Wearable Sensors and chair of the nanoengineering department at UC San Diego.
Existing self-healing materials require an external trigger to kick start the healing process. They also take anywhere between a few minutes to several days to work. By contrast, the system developed by Wang and colleagues doesn’t require any outside catalyst to work. Damage is repaired within about 50 milliseconds (0.05 seconds).
Engineers used the ink to print batteries, electrochemical sensors and wearable, textile-based electrical circuits (see video). They then set about damaging these devices by cutting them and pulling them apart to create increasingly wide gaps. Researchers repeatedly damaged the devices nine times at the same location. They also inflicted damage in four different places on the same device. The devices still healed themselves and recovered their function while losing a minimum amount of conductivity.
For example, nanoengineers printed a self-healing circuit on the sleeve of a T-shirt and connected it with an LED light and a coin battery. The researchers then cut the circuit and the fabric it was printed on. At that point, the LED turned off. But then within a few seconds it started turning back on as the two sides of the circuit came together again and healed themselves, restoring conductivity.
“We wanted to develop a smart system with impressive self-healing abilities with easy-to-find, inexpensive materials,” said Amay Bandodkar, one of the papers’ first authors, who earned his Ph.D. in Wang’s lab and is now a postdoctoral researcher at Northwestern University.
Wang’s research group is a leader in the field of printed wearable sensors, so his team of nanoengineers naturally turned to ink as a starting point for their self-healing system.
Engineers loaded the ink with microparticles made of a type of magnet commonly used in research and made of neodymium, a soft, silvery metal. The particles’ magnetic field is much larger than their individual size. This is the key to the ink’s self-healing properties because the attraction between the particles leads to closing tears that are millimeters wide.
The particles also conduct electricity and are inexpensive. But they have poor electrochemical properties, making them difficult to use in the electrochemical devices, such as sensors, on their own. To remedy this problem, researchers added carbon black to the ink, a material commonly used to make batteries and sensors.
But researchers realized that the microparticles’ magnetic fields, when in their natural configuration, canceled each other out, which robbed them of their healing properties. Engineers solved this by printing the ink in the presence of an external magnetic field, which ensured that the particles oriented themselves to behave as a permanent magnet with two opposite poles at the end of each printed device. When the device is cut in two, the two damaged pieces act as different magnets that attract each other and self-heal.
In the future, engineers envision making different inks with different ingredients for a wide range of applications. In addition, they plan to develop computer simulations to test different self-healing ink recipes in silico before trying them out in the lab.
Discovery could broaden effectiveness of emerging therapies for cancer and other diseases that are based on boosting the natural immune system response
Researchers at University of California San Diego School of Medicine and Moores Cancer Center have identified a strategy to maximize the effectiveness of anti-cancer immune therapy. The researchers identified a molecular switch that controls immune suppression, opening the possibility to further improving and refining emerging immunotherapies that boost the body’s own abilities to fight diseases ranging from cancer to Alzheimer’s and Crohn’s disease.
The findings are published in the September 19 online issue of Nature.
“Immunotherapies, such as T cell checkpoint inhibitors, are showing great promise in early treatments and trials, but they are not universally effective,” said Judith A. Varner, PhD, professor in the Departments of Pathology and Medicine at UC San Diego School of Medicine. “We have identified a new method to boost the effectiveness of current immune therapy. Our findings also improve our understanding of key mechanisms that control cancer immune suppression and could lead to the development of more effective immunotherapies.”
When confronted by pathogens, injury or disease, the initial response of the body’s immune system comes in the form of macrophages, a type of white blood cell that express pro-inflammatory proteins called cytokines that, in turn, activate T cells, another immune cell, to attack the health threat. The macrophages then switch gears to express other cytokines that dampen T cell activation, stimulating tissue repair.
In chronic inflammatory diseases such as Alzheimer’s and Crohn’s, however, macrophages associated with the malignancy continue to produce pro-inflammatory cytokines and other substances that kill or transform normal cells. In cancer, highly abundant microphages express anti-inflammatory cytokines that induce immune suppression, effectively stopping the healing process.
In the Nature paper, Varner and colleagues pinpoint a key, suspected player: an enzyme in macrophages called PI-3 kinase gamma (PI3Ky). In mouse studies, they found that macrophage PI3Ky signaling promotes immune suppression by inhibiting activation of anti-tumor T cells. Blocking PI3Ky activated the immune response and significantly suppressed growth of implanted tumors in animal models. It also boosted sensitivity of some tumors to existing anti-cancer drugs and synergized with existing immune therapy to eradicate tumors. Varner and her colleagues at the Moores Cancer Center also identified a molecular signature of immune suppression and response in mice and cancer patients that may be used to track the effectiveness of immunotherapy.
“Recently developed cancer immunotherapeutics, including T cell checkpoint inhibitors and vaccines, have shown encouraging results in stimulating the body’s own adaptive immune response,” said co-author Ezra Cohen, MD, who heads the cancer immunotherapy program at Moores Cancer Center. “But they are effective only on a subset of patients, probably because they do not alter the profoundly immunosuppressive microenvironment created by tumor-associated macrophages. Our work offers a strategy to maximize patient responses to immune therapy and to eradicate tumors. ”
The Nature paper builds upon other work by Varner and colleagues. In a paper first published online in May in Cancer Discovery, Varner’s team reported that blocking PI3Ky in tumor-associated macrophages stimulated the immune response and inhibited tumor cell invasion, metastasis and fibrotic scarring caused by pancreatic ductal adenocarcinoma (PDAC) in animal models.
In humans, PDAC is the most common malignancy of the pancreas It’s aggressive and difficult to treat. Though only the 12th most common type of cancer in the United States, pancreatic cancer is the fourth most common cause of cancer-related death.
“PDAC has one of the worst 5-year survival rates of all solid tumors, so new treatment strategies are urgently needed,” said Megan M. Kaneda, PhD, an assistant project scientist in Varner’s lab and collaborator on all of the papers.
In a December 2015 paper published online in Cancer Discovery, Varner and colleagues described animal studies that revealed how disrupting cross-talk between B cells (another type of immune cell) and tumor-associated macrophages inhibited PDAC growth and improved responsiveness to standard-of-care chemotherapy.
Specifically, that research team, which included scientists in San Francisco, Oregon and Switzerland, reported that inhibiting Bruton tyrosine kinase, an enzyme that plays a crucial role in B cell and macrophage functions, restored T cell-dependent anti-tumor immune response. In other words, it reactivated the natural, adaptive immune response in tested mice.
Researchers at University of California San Diego’s Big Pixel Initiative are using unique tools to map urban areas around the globe, potentially revolutionizing large-scale analysis of urbanization. Using Google Earth Engine, they developed and tested new machine-learning approaches that use high-resolution satellite data to detect and map settlements around the world.
These methods, detailed in the paper “Detecting the Boundaries of Urban Areas in India: A Dataset for Pixel-Based Image Classification from Google Earth Engine,” will eventually allow for the creation of a high-resolution map of all inhabited locations and for a better understanding of how cities expand and evolve. They provide, for the first time, a reliable and comprehensive open-source data for detecting and mapping urban areas through satellite images.
The paper appears in the August 2016 issue of Remote Sensing, one of the top peer-reviewed journals on satellite-based research. Authors are Big Pixel Initiative researchers Ran Goldblatt and Gordon Hanson of the School of Global Policy and Strategy, with UC San Diego Department of Economics doctoral candidate Wei You and Amit K. Khandelwal of Columbia Business School at Columbia University.
With the hope to provide a tool that can identify urbanization and industrialization to other researchers, the authors found there is currently no reliable open-source dataset to automatically detect urban areas and to validate the existing maps that currently exist. They explain that urbanization is a fundamental force that shapes almost all dimensions of the modern world, from land cover and land use around cities to economics and policy making. However, the rate and magnitude of these changes have not yet been mapped globally with sharp precision.
“With the availability of cloud-based platforms such as [Google Earth Engine], it is now feasible to monitor urbanization in multi-spatial and temporal resolutions and to understand urban dynamics globally,” the authors write. These platforms allow researchers to analyze geospatial data and to understand the rate and magnitude of urban growth, especially in regions and countries where maps of urban areas do not exist.
“Ours is the first to provide comprehensive open-source ground-truth data that can serve as a training set for supervised classification of built-up land cover,” they write. “Understanding the various ecological, environmental, social and economic impacts of these processes is essential for the preservation of a sustainable human society.”
Goldblatt and the team constructed a unique dataset of 21,030 manually classified image samples representing different forms of built-up and not built-up land cover in India. These samples were then used for supervised image classification designed to detect urban areas, performing the analysis in cloud-based Google Earth Engine. Their goal in part is to use high-resolution satellite-data to create a continuous map of the urbanization process: for the first time looking extensively over time and over large-scale areas.
“Expanding this research frontier creates an urgent need for ground-truth data that can facilitate the development of supervised machine-learning algorithms and enable reliable evaluation and validation,” they said. Although this research was designed to detect urban areas in India, the methodology can easily be applied to other countries and regions, and will have impacts for governments, policy makers, business and property development as well as humanitarian and environmental workers.
Founded by Hanson and Albert Yu-Min Lin of the Qualcomm Institute, the Big Pixel Initiative’s mission is to develop advanced geospatial capacity to address the world’s greatest challenges. The initiative was launched in 2015 by unique, two-year access to DigitalGlobe Foundation data, and then expanded to include analysis on the Google Earth Engine platform.
In working with geoscientists across campus and experts at Google, Hanson is leading the university’s efforts to measure urbanization worldwide using satellite imagery. “We want to be able to measure how cities grow and expand on the whole planet as closet to real time as we can, by using the vast amounts of satellite imagery that are coming online,” Hanson said.
A team of researchers has built a mathematical model that describes the molecular events associated with the beginning stage of learning and memory formation in the human brain.
The research, published in the journal Proceedings of the National Academy of Sciences, paves the way for understanding cognitive function and neurodegenerative diseases—at the molecular and cellular levels.
The study focuses on the dynamics of dendritic spines, which are thorny structures that allow neurons to communicate with each other. When a spine receives a signal from another neuron, it responds by rapidly expanding in volume—an event called transient spine expansion.
Transient spine expansion is one of the early events leading up to learning and memory formation. It consists of a cascade of molecular processes spanning four to five minutes, beginning when a neuron sends a signal to another neuron.
Many of the molecular processes leading up to transient spine expansion have already been identified experimentally and reported in the literature. Here, the authors built a map of many of these known processes into a computational framework.
“Spines are dynamic structures, changing in size, shape and number during development and aging. Spine dynamics have been implicated in memory, learning and various neurodegenerative and neurodevelopmental disorders, including Alzheimer’s, Parkinson’s and autism. Understanding how the different molecules can affect spine dynamics can eventually help us demystify some of these processes in the brain,” said Padmini Rangamani, a mechanical engineering professor at the University of California San Diego and first author of the study.
“This work shows that dendritic spines, which are sub-micrometer compartments within individual neurons, are the prime candidates for the initial tag of transient, millisecond synaptic activity that eventually orchestrates memory traces in the brain lasting tens of years,” said Shahid Khan, senior scientist at the Molecular Biology Consortium at Lawrence Berkeley National Laboratory and a co-author on the PNAS paper.
In this study, researchers constructed a mathematical model, based on ordinary differential equations, linking the different molecular processes associated with spine expansion together. They identified the key components (molecules and enzymes) and chemical reactions that regulate spine expansion.
As a result, they observed an interesting pattern—that the same components could both turn on and off some of the steps in the sequence—a phenomenon called paradoxical signaling. Further, they linked the chemical reactions of the different molecules to the reorganization of the actin cytoskeleton, which gives the cell its shape.
Both of these features—paradoxical signaling and linking spine expansion to actin reorganization—make this model robust, Rangamani explained. “By putting all these complicated pieces together in a simple mathematical framework, we can start to understand the underlying mechanisms of spine expansion. This is one of the benefits of combining mechanics of the cytoskeleton and biochemistry. We can bring together pieces of experimental work that are often not seen. However, we should note that we are only at the beginning stages of understanding what spines, neurons and the brain can do.”
“This work is notable for bringing together aspects from diverse disciplines (systems biology, cell signaling, actin mechanobiology and proteomics) and should motivate similar multi-disciplinary efforts for other problems in fundamental cellular neuroscience,” Khan said.