Reactive stamps remove molecules from surfaces to create precise nanoscale patterns.( Credit: Image courtesy University of California- Los Angels)
Fabricating precise biomolecular structures at extremely small scales is critical to the progress of nanotechnology and related fields.
Traditionally, one of the ways this has been accomplished has been through the use of rubber stamps with tiny features — similar to those used by children in play, but detailed at the microscopic scale — which are covered with molecular “inks” and then stamped onto substrate surfaces, creating a molecular patterns. But when using this technique at the nanoscale, molecules tend to diffuse on the surface both during and after stamping, blurring the patterns.
To address this problem, researchers at UCLA have turned this conventional “soft lithography” process on its head: Instead of using a stamp to transfer molecules onto bare surfaces, they have used chemically treated stamps to remove molecules already in place on gold substrates, essentially peeling away select molecules through chemical bonds to create precise patterns measuring just a few molecules across.
The new process, called chemical lift-off lithography (CLL), results in higher-resolution patterning and avoids the blurring problems of earlier techniques.
The findings are published Sept. 20 in the journal Science. The research was supported by the U.S. Department of Energy and the Kavli Foundation.
The stamp used in the new process is molded by using a “master” made with more sophisticated and expensive tools than those used in making rubber stamps for offices and children, but the stamps can be used over and over again. Between each use, they are simply reactivated by an oxygen plasma.
The chemical bonds formed at the stamp—substrate interface are sufficiently strong to remove not only molecules in the monolayers but also one layer of gold atoms from the substrate. This observation settled a long-running discussion over whether, for such monolayers, gold–gold bonds break more easily than molecule–gold bonds — they do, the researchers found.
The research team was able to fabricate a variety of high-resolution patterned features, and stamps were cleaned and reused many times with little feature deterioration. The remaining monolayer, they found, can act as a resist for etching exposed gold features. The backfilling of new molecules into the lifted-off areas enabled patterned protein capture, and sharp 40 nanometer chemical patterns were achieved.
Led by Anne Andrews and Paul Weiss, the UCLA team represents a collaboration among researchers from UCLA’s California NanoSystems Institute, the Semel Institute for Neuroscience and Human Behavior at UCLA, and the departments of chemistry and biochemistry, materials science and engineering, and psychiatry and biobehavioral sciences.
Conventional nanolithographic patterning techniques, such as photolithography and electron-beam lithography, are expensive, time-consuming, require specialized equipment and instrumentation, and have limited capabilities for chemical patterning; here, they only need to be used for the fabrication of stamp master molds.
Once individual masters are produced, CLL is used for high-resolution, high-throughput, low-cost pattern fabrication. This method enables patterns to be transferred to underlying substrates, and multiple-stamping strategies can be used to produce high-fidelity nanometer-scale patterns on gold substrates, with the additional possibility of patterning different materials, such as silicon, germanium, platinum and graphene.
The patterns fabricated demonstrate that CLL not only transfers large-area, high-fidelity patterns, but the post–lift-off exposed gold areas are advantageous for producing multiplexed patterned surfaces for selective capture of biomolecules from complex mixtures.
EPR spectrometer at UCSB (Credit: Susumu Takahashi)
A multi-university team has employed a high-powered laser based at UC Santa Barbara to dramatically improve one of the tools scientists use to study the world at the atomic level. The team used their amped-up electron paramagnetic resonance (EPR) spectrometer to study the electron spin of free radicals and nitrogen atoms trapped inside a diamond.
The improvement will pull back the veil that shrouds the molecular world, allowing scientists to study tiny molecules at a high resolution.
The team, which includes researchers from UCSB, University of Southern California (USC), and Florida State University, published its findings this week in Nature.
“We developed the world’s first free-electron laser-powered EPR spectrometer,” said Susumu Takahashi, assistant professor of chemistry at the USC Dornsife College of Letters, Arts and Sciences, and lead author of the Nature paper. “This ultra high-frequency, high-power EPR system gives us extremely good time resolution. For example, it enables us to film biological molecules in motion.”
By using a high-powered laser, the researchers were able to significantly enhance EPR spectroscopy, which uses electromagnetic radiation and magnetic fields to excite electrons. These excited electrons emit electromagnetic radiation that reveals details about the structure of the targeted molecules.
EPR spectroscopy has existed for decades. Its limiting factor is the electromagnetic radiation source used to excite the electrons –– it becomes more powerful at high magnetic fields and frequencies, and, when targeted, electrons are excited with pulses of power as opposed to continuous waves.
Until now, scientists performed pulsed EPR spectroscopy with a few tens of GHz of electromagnetic radiation. Using UCSB’s free electron laser (FEL), which emits a pulsed beam of electromagnetic radiation, the team was able to use 240 GHz of electromagnetic radiation to power an EPR spectrometer.
“Each electron can be thought of as a tiny magnet that senses the magnetic fields caused by atoms in its nano-neighborhood,” said Mark Sherwin, professor of physics and director of the Institute for Terahertz Science and Technology at UCSB. “With FEL-powered EPR, we have shattered the electromagnetic bottleneck that EPR has faced, enabling electrons to report on faster motions occurring over longer distances than ever before. We look forward to breakthrough science that will lay foundations for discoveries like new drugs and more efficient plastic solar cells.”
University of Rochester Medical Center scientists discovered new genetic evidence linking cholesterol and cancer, raising the possibility that cholesterol medications could be useful in the future for cancer prevention or to augment existing cancer treatment.
The data, published in the online journal Cell Reports, support several recent population-based studies that suggest individuals who take cholesterol-lowering drugs may have a reduced risk of cancer, and, conversely that individuals with the highest levels of cholesterol seem to have an elevated risk of cancer.
The cancer-cholesterol question has been debated since the early 20th century, and along with it doctors and scientists have observed various trends and associations. However, until now genetic evidence directly linking cholesterol and malignancy has been lacking, said senior author Hartmut (Hucky) Land, Ph.D., Robert and Dorothy Markin Professor and chair, Department of Biomedical Genetics, and director of research and co-director of the James P. Wilmot Cancer Center at URMC.
Cholesterol is a fat-like substance supplied in foods and made in cells throughout the body. Too much cholesterol is bad for the heart and vascular system. It is typically measured as serum cholesterol by routine blood tests.
Unlike serum cholesterol that is bound to proteins, however, cholesterol also hides inside cells. While locked inside cell membranes before it is eventually exported, cholesterol has an impact on cell growth and survival. A gene, known as ABCA1, is at the crossroads of the process that shuttles intracellular cholesterol outbound.
Several years ago while conducting unrelated experiments that were published in the journal Nature, Land and colleagues first noticed the importance of ABCA1. At that time, they identified a network of approximately 100 so-called “cooperation response genes” that mediate the action of cancer genes. ABCA1 was found among these genes and is frequently turned off in presence of other mutant cancer genes.
In the latest investigation, Land and co-author Bradley Smith, Ph.D., a post-doctoral fellow in the Land lab, wanted to further understand the role of ABCA1 and cholesterol in cancer. They found that defective cholesterol exportation appears to be a key component in a variety of cancers.
The proper function of ABCA1 is critical for sensing of cell stress. If ABCA1 function is lost in cancer cells, cholesterol is allowed to build up in the cells’ mitochondria, or energy centers, making their membranes more rigid. This in turn inhibits the function of cell-death triggers that normally become activated in response to cell stresses, as for example cancer gene activation. Therefore, when functioning properly, ABCA1 has anti-cancer activity – in the sense that by keeping mitochondrial cholesterol low it protects the functioning of cellular stress response systems and acts as a barrier to tumor formation and progression.
Smith and Land also demonstrated that some of the relatively rare ABCA1 mutations found in human colon cancers by other investigators disabled the gene’s ability to export cholesterol. And by re-establishing the cholesterol export function in human colon cancer cells, they inhibited the cells’ ability to grow as cancers when grafted onto mice.
The URMC study, therefore, is the first to directly show how ABCA1 loss-of-function and cholesterol may play a role in cancer. “Scientifically it is very satisfying to have data that support longstanding ideas about cholesterol in the context of cancer,” Land said. “Our paper provides a rationale for cholesterol targeting as a potentially fruitful approach to cancer intervention or prevention strategies.”
Millions of Americans take cholesterol-lowering drugs or statins, as prescribed by physicians. Clinical trials also are evaluating statins as a tool against cancer, and some previous studies suggest that when used in combination with chemotherapy, statins might make chemotherapy more effective by sensitizing certain cancer cells to chemotherapy-induced cell death.
Land, however, urges caution and further study. Doctors do not know the appropriate statin dose for cancer prevention or treatment of cancer-related conditions. Side effects cannot be ignored either, and little research has distinguished between the responses among people who take statins.
“The link between cholesterol and cancer is clear,” Land said, “but it’s premature to say that statins are the answer.”
Dr. Ian Neeland, a cardiology fellow and first author of the paper (left); and Dr. James de Lemos, professor of internal medicine (Credit: UT Southwestern Medical Center)
Obese individuals with excess visceral fat (abdominal fat that surrounds the body’s internal organs) have an increased risk for the development of type 2 diabetes, according to a new study by researchers at UT Southwestern Medical Center. By contrast, persons with excess abdominal subcutaneous fat (fat underneath the skin) were not at higher risk for the onset of diabetes.
The study, published in the September obesity-themed issue of the Journal of the American Medical Association, is one of the largest of its kind to assess a multiethnic population of obese people in the U.S. using extensive imaging of adipose tissue. The findings are being presented today in New York at a media briefing hosted by JAMA.
“Among obese individuals, it is not necessarily how much fat a person has, but rather where the fat is located on a person that leads to diabetes,” according to the paper’s senior author, Dr. James de Lemos, professor of internal medicine at UT Southwestern.
Using imaging methods to determine the location and function of body fat, researchers are able to identify obese persons who are at a higher risk for developing type 2 diabetes years before the disease appears.
“Understanding the biological differences between visceral fat and subcutaneous fat may help doctors to more effectively battle the obesity epidemic occurring in the United States,” Dr. de Lemos said. “The risk for diabetes varies widely among different obese individuals, and this study suggests that by predicting who will get diabetes, it may be possible to target intensive lifestyle, medical, and surgical therapies for those at a higher risk.”
The study, which collected information from UT Southwestern’s Dallas Heart Study, sampled 732 obese adults – those with a body mass index of 30 or greater – between the ages of 30 and 65, without diabetes or cardiovascular disease.
Researchers utilized magnetic resonance imaging (MRI) and dual energy X-ray absorptiometry (DEXA) to determine where fat was stored in the body. While other studies have weighed people and used tape measures to assess their body fat, this study included the largest number of obese people to undergo extensive body-fat imaging.
When participants returned for a follow-up after seven years, researchers found that 11 percent of the people sampled developed diabetes. Among the participants who had normal glucose at baseline testing, 39 percent developed prediabetes or diabetes. Prediabetes is believed to be an intermediate state between normal metabolic function and diabetes. Those who developed prediabetes and diabetes had higher amounts of visceral fat and greater insulin resistance compared to those who remained healthy.
“We found that individuals who developed prediabetes and diabetes had evidence of early cardiovascular disease years before the onset of diabetes,” said Dr. Ian Neeland, a cardiology fellow and first author of the paper. “This finding suggests that excess visceral fat and insulin resistance may contribute to cardiovascular disease among obese individuals.”
The Dallas Heart Study is a multi-ethnic population-based study of 6,101 adults from Dallas County. Among other things, the investigation – begun in 1999 – was designed to identify new genetic, protein, and imaging biomarkers that can detect cardiovascular disease at its earliest stages, when treatment is most effective. This research, funded by the Donald W. Reynolds Foundation, involved numerous noted UT Southwestern scientists and physicians, including Dr. Helen Hobbs, director of the Eugene McDermott Center for Human Growth and Development, and Dr. Eric Olson, chairman of molecular biology.
More information about the Dallas Heart Study is available online:
Doubt is not a pleasant mental state, but certainty is a ridiculous one.
In the first scientific study to test whether doubts about getting married are more likely to lead to an unhappy marriage and divorce, UCLA psychologists report that when women have doubts before their wedding, their misgivings are often a warning sign of trouble if they go ahead with the marriage.
The UCLA study demonstrates that pre-wedding uncertainty, especially among women, predicts higher divorce rates and less marital satisfaction years later.
“People think everybody has premarital doubts and you don’t have to worry about them,” said Justin Lavner, a UCLA doctoral candidate in psychology and lead author of the study. “We found they are common but not benign. Newlywed wives who had doubts about getting married before their wedding were two-and-a-half times more likely to divorce four years later than wives without these doubts. Among couples still married after four years, husbands and wives with doubts were significantly less satisfied with their marriage than those without doubts.
“You know yourself, your partner and your relationship better than anybody else does; if you’re feeling nervous about it, pay attention to that,” he added. “It’s worth exploring what you’re nervous about.”
The psychologists studied 464 newlywed spouses (232 couples) in Los Angeles within the first few months of marriage and conducted follow-up surveys with the couples every six months for four years. At the time of marriage, the average age of the husbands was 27, and the average age of the wives was 25. The research is published in the online version of the Journal of Family Psychology, published by the American Psychological Association, and will appear in an upcoming print edition.
When asked, “Were you ever uncertain or hesitant about getting married?” at their initial interview, 47 percent of husbands and 38 percent of wives said yes. Yet while women were less likely than men to have doubts, their doubts were more meaningful in predicting trouble after the wedding, the researchers found.
Among women, 19 percent of those who reported pre-wedding doubts were divorced four years later, compared with 8 percent of those who did not report having doubts. For husbands, 14 percent who reported premarital doubts were divorced four years later, compared with 9 percent who did not report having doubts.
Doubt proved to be a decisive factor, regardless of how satisfied the spouses were with their relationships when interviewed, whether their parents were divorced, whether the couple lived together before the wedding and how difficult their engagement was.
In 36 percent of couples, the husband and wife had no doubts about getting married. Of those couples, 6 percent got divorced within four years. When only the husband had doubts, 10 percent of the couples got divorced. When only the wife had doubts, 18 percent of couples got divorced. When both partners had doubts, 20 percent of the couples got divorced.
“What this tells us,” Lavner said, “is that when women have doubts before their wedding, these should not be lightly dismissed. Do not assume your doubts will just go away or that love is enough to overpower your concerns. There’s no evidence that problems in a marriage just go away and get better. If anything, problems are more likely to escalate.”
Thomas Bradbury, a UCLA psychology professor and co-author of the study, compared the situation to finding something disturbing on your skin that you hadn’t noticed before.
“If you see something unusual on your skin, should you ignore it and go to the beach, or see a doctor? Be smart and don’t ignore it — and don’t ignore your doubts either,” said Bradbury, who co-directs the Relationship Institute at UCLA. “Have a conversation and see how it goes. Do you think the doubts will go away when you have a mortgage and two kids? Don’t count on that.”
The psychologists are not advising women with doubts to necessarily end the relationship, they say.
“Talk about it and try to work through it,” Bradbury said. “You hope that the big issues have been addressed before the wedding.”
Benjamin Karney, a UCLA professor of psychology and co-director of the Relationship Institute at UCLA, was a co-author of the study.
The research was federally funded by the National Institute of Mental Health (part of the National Institutes of Health) and the National Science Foundation, as well as by UCLA’s Academic Senate.
A cure for deafness is a step closer after University of Sheffield scientists used human embryonic stem cells to treat a common form of hearing loss.
In research funded by the Medical Research Council and leading UK research charity, Action on Hearing Loss, experts from the University’s Department of Biomedical Sciences developed a method to turn human embryonic stem cells into ear cells.
They then transplanted them into deaf gerbils, obtaining a functional recovery that, on average, was of around 46 per cent. The improvement was evident about four weeks after administering the cells.
Human stem cell-derived otic neurons repopulating the cochlea of deaf gerbils. Human cells are labelled green, and the red is a marker of neuronal differentiation. Therefore yellow cells are neurons of human origin (Credit: Image courtesy of The University of Sheffield)
As well as proving that stem cells can be used to repair damaged hearing, it is hoped the breakthrough – published in the journal Nature – will lead to new treatments and therapies in the future.
The model of hearing loss successfully treated by the scientists is similar to a human condition known as auditory neuropathy, a form of deafness in which the damage occurs at the level of the cochlear nerve. It is thought to represent up to 15 per cent of the population across the world with profound hearing loss.
Dr Marcelo Rivolta, who led the project, said: “We developed a method to drive human embryonic stem cells to produce both hair cells and neurons, or nerve cells, but we only transplanted the neurons. We then used a technique called auditory brainstem evoked responses (ABR), which measures if the brain can perceive an electrical signal after sound stimulation. The responses of the treated animals were substantially better than those untreated, although the range of improvement was broad. Some subjects did very well, while in others recovery was poor.”
Auditory neuropathy is a type of deafness where the problem lies, not primarily with the hair cells, but in the connection of the hair cells with the brain. Patients can be born with it and there are cases due to a genetic defect where a few responsible genes have already been identified.
However, there is increasing evidence that environmental factors, such as jaundice at birth and noise exposure later in life, play an important role, at least as risk factors.
Dr Rivolta added: “We believe this an important step forward. We have now a method to produce human cochlear sensory cells that we could use to develop new drugs and treatments, and to study the function of genes. And more importantly, we have the proof-of-concept that human stem cells could be used to repair the damaged ear.
“More research is needed. For instance, we want to understand the long term implications of this treatment and its safety. Moreover, while in auditory neuropathy patients that retain their hair cells the sole application of stem cells could be beneficial; those with more comprehensive damage may need a cochlear implant to compensate for the hair cell deficit. In these patients it is possible that stem cells should be administered in combination with a cochlear implant. It is therefore important to explore this interaction.”
Dr Ralph Holme, Head of Biomedical Research for Action on Hearing Loss, said: “The research we have funded at the University of Sheffield is tremendously encouraging and gives us real hope that it will be possible to fix the actual cause of some types of hearing loss in the future. For the millions of people for whom hearing loss is eroding their quality of life, this can’t come soon enough.”
Dr Paul Colville-Nash, Programme Manager for stem cell, developmental biology and regenerative medicine at the Medical Research Council, which co-funded the research, added: “This is promising research that demonstrates further proof-of-concept that stem cells have the potential to treat a range of human diseases that currently have no effective cures. While any new treatment is likely to take years to reach the clinic, this study clearly demonstrates that investment in UK stem cell research and regenerative medicine is beginning to bear fruit, and that is very exciting.”
Bucking the idea that environmentalism hurts economic performance, a new UCLA-led study has found that companies that voluntarily adopt international “green” practices and standards have employees who are 16 percent more productive than the average.
Professor Magali Delmas, an environmental economist at UCLA’s Institute of the Environment and Sustainability and the UCLA Anderson School of Management, and Sanja Pekovic from France’s University Paris–Dauphine are the first to study how a firm’s environmental commitment affects its productivity.
Their findings are published online Sept. 10 in the Journal of Organizational Behavior.
“Adopting green practices isn’t just good for the environment,” Delmas said. “It’s good for your employees and it’s good for your bottom line. Employees in such green firms are more motivated, receive more training, and benefit from better interpersonal relationships. The employees at green companies are therefore more productive than employees in more conventional firms.”
For their study, “Environmental Standards and Labor Productivity: Understanding the Mechanisms That Sustain Sustainability,” Delmas and Pekovic collected data from a survey of employees at 5,220 French companies, randomly selecting two employees from each company for a pool of more than 10,000 people. Companies that had voluntarily adopted international standards and eco-labels such as “fair trade” and “organic” or the International Organization for Standardization’s ISO 14001 certification were identified as green.
The researchers determined each company’s productivity by taking a logarithm of its value added (revenue minus costs), divided by the number of employees, which produced the average value of production per employee. They discovered a difference of one standard deviation, which corresponded to 16 percent higher-than-average labor productivity, in firms that voluntarily adopted environmental standards.
The employee surveys showed how much training employees received and how often they interacted with co-workers — which Delmas and Pekovic found also correlated with green companies.
“It’s truly a big difference between firms that have adopted these practices and firms that haven’t,” Delmas said. “I expected a contrast, but not such a strong, robust jump in productivity.”
Green certifications should be used by managers to increase productivity, by potential employees as a sign of a better work environment, and by investors as an indicator of good management practices, Delmas said. Previous research has already shown that sustainable business practices can result in cost-efficiencies, but Delmas and Pekovic are the first to explore the link to labor productivity.
“It’s a counterpoint to people thinking that environmental practices are detrimental to the firm,” Delmas said. “Green practices make a company more attractive because so many employees want to work for a company that is green, but we also argue in this paper that it’s more than just wanting to work there — it’s working more.”
The findings reflect a change in attitudes, according to Delmas.
“When you talk now to M.B.A. students, there’s a big change in the way they look at their future job,” she said. “They don’t want to work just to make money. They also want to make a difference. There’s a little more social consciousness than there was before.”
The ‘virtuous circle’
Because fair trade, organic and ISO 14001 are international certifications that are commonly used in the United States, the findings are applicable in the U.S. and around the world, the authors said.
All three eco-labels are third-party certified: Fair trade certification requires fair wages and treatment for employees; organic certification recognizes commitments such as working without pesticides and other chemicals; and ISO 14001 certification requires firms to set up an organizational structure to investigate the company’s environmental impact and how to reduce it.
The higher-productivity effect stems from employees’ appreciation for their workplace, Delmas said. The certifications, especially ISO 14001, include educating employees about a firm’s environmental commitment and require employees to work together across departments to reduce the organization’s environmental impact. This education and training helps increase employees’ identification with their office, while interdepartmental cooperation increases employees’ engagement.
“It’s a virtuous circle,” Delmas said — the opposite of a vicious cycle. “You attract the best people, and because you’re open-minded, then you adopt green standards, and then you attract even better people, and this continues to feed itself. Companies that adopt these policies tend to be better. It could be they were better to start with, but there are mechanisms built into these policies that mean they continue to get better.”
Although the companies from the survey retain confidentiality, it’s an effect Delmas said she has seen elsewhere many times. At Patagonia, a sports-clothing company well known for its sustainable practices, every job opening receives an average of 900 applicants eager to work for a green company, she said. At the Ambrose Hotel, a boutique hotel in Santa Monica, Calif., adopting wide-ranging sustainability measures made employees happier and healthier, Delmas found in a case study. Housekeeping workers reported fewer headaches, allergies and sick days after switching from chemical cleaners to non-toxic, green cleaning products.
In her research, Delmas has found that wineries also adopt the organic label to improve employees’ health.
“I hope managers look at this and see the potential for their firms and employees,” she said. “Socially responsible investors say green practices are a proxy for good management. It’s also important for regulators to see that some voluntary practices can have beneficial effects.”
A multidisciplinary team of researchers from UCLA and other universities is poised to help turn science fiction into reality — in the form of some of the world’s tiniest electromagnetic devices — thanks to a major grant from the National Science Foundation’s Engineering Research Center (ERC) program.
The grant, worth up to $35 million over 10 years, will fund a new center headquartered at UCLA’s Henry Samueli School of Engineering and Applied Science that will focus on research aimed at developing highly efficient and powerful electromagnetic systems roughly the size of a biological cell — systems that can power a range of devices, from miniaturized consumer electronics and technologies important for national security to as-yet unimagined machines, like nanoscale submarines that can navigate through the human blood stream.
Employing a fundamentally new approach to electromagnetic power at the nanoscale, researchers at the NSF-funded TANMS center (Translational Applications of Nanoscale Multiferroic Systems) are working to replace traditional wire-based electronics with a revolutionary technique that couples electricity and magnetism by using multiferroic materials, which can be magnetically switched “on” and “off” by an electric field.
UCLA’s partners in the new center include UC Berkeley, Cornell University, Switzerland’s ETH Zurich and California State University, Northridge.
“At UCLA, we strive to conduct research that pushes the boundaries of knowledge and benefits society in practical ways, and this new center is a prime example of that pursuit,” UCLA Chancellor Gene Block said. “The National Science Foundation award for this major research center reflects the excellence and commitment of our renowned faculty and the quality of their collaborations with colleagues at other institutions.”
“TANMS could spur a true paradigm shift for new devices that were once thought of as science fiction but now appear just over the horizon,” said Vijay K. Dhir, dean of UCLA Engineering. “This new engineering research center’s roster includes world-class faculty, and along with the best students in world, they will create and develop amazing new technologies that will certainly be exciting to see.”
“We believe this is an opportunity for a truly revolutionary change in miniaturized electromagnetic devices,” said Greg Carman, director of the new center and a UCLA professor of mechanical and aerospace engineering professor. “If you combine all three of our application areas — memory, antennas and motors — it really opens the possibilities of what new platforms may become possible. For example, it might be possible to build a remote submarine similar to the one described in the 1960s movie ‘Fantastic Voyage.’ Imagine a miniature submarine, at length-scales similar to red blood cells, that could be controlled and move through the blood stream.
“Present electromagnetic devices are based on concepts discovered nearly 200 years ago, and, while working well in large systems, they suffer from severe limitations in the small scale,” he added. “TANMS overcomes this problem by developing a new, game-changing approach to produce electromagnetic fields using nanoscale multiferroic materials with lengths as small as a few hundred atoms.”
Electromagnetic devices are ubiquitous in today’s world, from smart phones and computers to the simple motors that automatically roll up car windows. All of these devices operate by passing an electric current through a wire, a concept first demonstrated in the early 1800s. And while this technology works extremely well in the large scale, it fails in the small scale and has been a roadblock to advancements in miniaturization. Much like water flowing through a pipe, as a wire’s diameter decreases, so does the amount of current flowing through it, limiting the ability of this current–through-a-wire approach to create and control electromagnetic energy.
The new approach being developed by TANMS researchers seeks to solve this problem by taking advantage of multiferroic materials, which use electric fields to intrinsically switch the magnetic state of a material, similar to switching a light bulb on and off. Over the past decade, these researchers have led explorative efforts demonstrating the unique properties present in multiferroics at the nanoscale. These discoveries are leading to an entirely new method of controlling electromagnetic devices to revolutionize antennas, memory and motors at extremely small scales — an approach previously considered implausible.
“With platform technologies such as the ones we are developing, new, active devices that are more efficient, substantially smaller and more powerful will be available to engineers working on a wide class of problems, including the critical-care needs facing our nation,” said Carman, who is a member of the California NanoSystems Institute at UCLA. “Of course, each individual focus application represents a significant advancement. For example, the ability to decrease the antenna size in a cell phone by an order of magnitude is an important step not only for consumers but also the military. I feel very fortunate to lead the world’s best academic researchers in nanoscale multiferroics, and the whole team is truly excited about the unique opportunities and discoveries that await us during this 10-year NSF program.”
While the new center’s major focus is on research, it also aims to develop a unique ecosystem around the five-university alliance focused on both education and commercialization. TANMS faculty are already working closely with UCLA’s Institute for Technology Advancement to help define and transition to market the intellectual property that will be developed under the new program. And 21 companies, ranging from small businesses to large corporations, have sent letters of interest to help translate and commercialize TANMS discoveries.
On the educational front, TANMS has a unique “cradle-to-career” program that will introduce high school students to the center’s facilities, as well as provide them with unique opportunities throughout their college careers. TANMS’s educational philosophy focuses on teaching students about the important interactions between the engineering and business sectors that are necessary to advance new technologies that benefit society.
“The United States always led in technology development during the last century, and to continue this, our country needs to expand the pipeline of future engineers and scientists with more students from diverse backgrounds,” Carman said. “At TANMS, we envision high school students, undergraduates and graduate students all taking part in both research and translational efforts associated with the research. We are trying to help our best and brightest students find their path toward being the next Henry Ford, Steve Jobs or Henry Samueli. I firmly believe that teaching our students that engineering is as much about business as it is about science will lead to a new wave students interested in entering engineering school, and I expect our new paradigm to become a model program for other universities across the country.”
Coral reefs face severe challenges even if global warming is restricted to the 2 degrees Celsius commonly perceived as safe for many natural and man-made systems. Warmer sea surface temperatures are likely to trigger more frequent and more intense mass coral bleaching events. Only under a scenario with strong action on mitigating greenhouse-gas emissions and the assumption that corals can adapt at extremely rapid rates, could two thirds of them be safe, shows a study now published in Nature Climate Change. Otherwise all coral reefs are expected to be subject to severe degradation.
Coral reefs house almost a quarter of the species in the oceans and provide critical services – including coastal protection, tourism and fishing – to millions of people worldwide. Global warming and ocean acidification, both driven by human-caused CO2 emissions, pose a major threat to these ecosystems.
“Our findings show that under current assumptions regarding thermal sensitivity, coral reefs might no longer be prominent coastal ecosystems if global mean temperatures actually exceed 2 degrees Celsius above the pre-industrial level,” says lead author Katja Frieler from the Potsdam Institute for Climate Impact Research. “Without a yet uncertain process of adaptation or acclimation, however, already about 70% of corals are projected to suffer from long-term degradation by 2030 even under an ambitious mitigation scenario.” Thus, the threshold to protect at least half of the coral reefs worldwide is estimated to be below 1.5 degrees Celsius mean temperature increase.
A more comprehensive and robust representation than in previous studies
This study is the first comprehensive global survey of coral bleaching to express results in terms of global mean temperature change. It has been conducted by scientists from Potsdam, the University of British Columbia in Canada and the Universities of Melbourne and Queensland in Australia. To project the cumulative heat stress at 2160 reef locations worldwide, they used an extensive set of 19 global climate models. By applying different emission scenarios covering the 21st century and multiple climate model simulations, a total of more than 32,000 simulation years was diagnosed. This allows for a more robust representation of uncertainty than any previous study.
Corals derive most of their energy, as well as most of their famous color, from a close symbiotic relationship with a special type of microalgae. The vital symbiosis between coral and algae can break down when stressed by warm water temperatures, making the coral “bleach” or turn pale. Though corals can survive this, if the heat stress persists long enough the corals can die in great numbers. “This happened in 1998, when an estimated 16% of corals were lost in a single, prolonged period of warmth worldwide,” says Frieler.
Adaptation is uncertain and ocean acidification means even more stress
To account for a possible acclimation or adaptation of corals to thermal stress, like shifts to symbiont algae with a higher thermal tolerance, rather optimistic assumptions have been included in the study. “However, corals themselves have all the wrong characteristics to be able to rapidly evolve new thermal tolerances,” says co-author Ove Hoegh-Guldberg, a marine biologist at the University of Queensland in Australia. “They have long lifecycles of 5-100 years and they show low levels of diversity due to the fact that corals can reproduce by cloning themselves. They are not like fruit flies which can evolve much faster.”
Previous analyses estimated the effect of thermal adaptation on bleaching thresholds, but not the possible opposing effect of ocean acidification. Seawater gets more acidic when taking up CO2 from the atmosphere. This is likely to act to the detriment of the calcification processes crucial for the corals’ growth and might also reduce their thermal resilience. The new study investigates the potential implications of this ocean acidification effect, finding that, as Hoegh-Guldberg says: “The current assumptions on thermal sensitivity might underestimate, not overestimate, the future impact of climate change on corals.”
This comprehensive analysis highlights how close we are to a world without coral reefs as we know them. “The window of opportunity to preserve the majority of coral reefs, part of the world’s natural heritage, is small,” summarizes Malte Meinshausen, co-author at the Potsdam Institute for Climate Impact Research and the University of Melbourne. “We close this window, if we follow another decade of ballooning global greenhouse-gas emissions.”
Source: Potsdam Institute for Climate Impact Research (PIK)
An international team of researchers, led by scientists at the University of California, San Diego and Yale University schools of medicine, have identified a form of autism with epilepsy that may potentially be treatable with a common nutritional supplement.
The findings are published in the September 6, 2012 online issue of Science.
Roughly one-quarter of patients with autism also suffer from epilepsy, a brain disorder characterized by repeated seizures or convulsions over time. The causes of the epilepsy are multiple and largely unknown. Using a technique called exome sequencing, the UC San Diego and Yale scientists found that a gene mutation present in some patients with autism speeds up metabolism of certain amino acids. These patients also suffer from epileptic seizures. The discovery may help physicians diagnose this particular form of autism earlier and treat sooner.
The researchers focused on a specific type of amino acid known as branched chain amino acids or BCAAs. BCAAs are not produced naturally in the human body and must be acquired through diet. During periods of starvation, humans have evolved a means to turn off the metabolism of these amino acids. It is this ability to shut down that metabolic activity that researchers have found to be defective in some autism patients.
“It was very surprising to find mutations in a potentially treatable metabolic pathway specific for autism,” said senior author Joseph G. Gleeson, MD, professor in the UCSD Department of Neurosciences and Howard Hughes Medical Institute investigator. “What was most exciting was that the potential treatment is obvious and simple: Just give affected patients the naturally occurring amino acids their bodies lack.”
Gleeson and colleagues used the emerging technology of exome sequencing to study two closely related families that have children with autism spectrum disorder. These children also had a history of seizures or abnormal electrical brain wave activity, as well as a mutation in the gene that regulates BCAAs. In exome sequencing, researchers analyze all of the elements in the genome involved in making proteins.
In addition, the scientists examined cultured neural stem cells from these patients and found they behaved normally in the presence of BCAAs, suggesting the condition might be treatable with nutritional supplementation. They also studied a line of mice engineered with a mutation in the same gene, which showed the condition was both inducible by lowering the dietary intake of the BCAAs and reversible by raising the dietary intake. Mice treated with BCAA supplementation displayed improved neurobehavioral symptoms, reinforcing the idea that the approach could work in humans as well.
“Studying the animals was key to our discovery,” said first author Gaia Novarino, PhD, a staff scientist in Gleeson’s lab. “We found that the mice displayed a condition very similar to our patients, and also had spontaneous epileptic seizures, just like our patients. Once we found that we could treat the condition in mice, the pressing question was whether we could effectively treat our patients.”
Using a nutritional supplement purchased at a health food store at a specific dose, the scientists reported that they could correct BCAA levels in the study patients with no ill effect. The next step, said Gleeson, is to determine if the supplement helps reduce the symptoms of epilepsy and/or autism in humans.
“We think this work will establish a basis for future screening of all patients with autism and/or epilepsy for this or related genetic mutations, which could be an early predictor of the disease,” he said. “What we don’t know is how many patients with autism and/or epilepsy have mutations in this gene and could benefit from treatment, but we think it is an extremely rare condition.”
Co-authors are Paul El-Fishawy, Child Study Center, Yale University School of Medicine; Hulya Kayserili, Medical Genetics Department, Istanbul University, Turkey; Nagwa A. Meguid, Rehab O. Khalil, Adel F. Hashish and Hebatalla S. Hashem, Department of Research on Children with Special Needs, National Research Centre, Cairo, Egypt; Eric M. Scott, Jana Schroth, Jennifer L. Silhavy, Neurogenetics Laboratory, Howard Hughes Medical Institute, Department of Neurosciences, UC San Diego; Majdi Kara, Pediatric Department, Tripoli Children’s Hospital, Libya; Tawfeq Ben-Omran, Clinical and Metabolic Genetics Division, Department of Pediatrics, Hamad Medical Corporation, Doha, Qatar; A. Gulhan Ercan-Sencicek, Stephan J. Sanders and Matthew W. State, Program on Neurogenetics, Child Study Center, Department of Psychiatry and Department of Genetics, Yale University School of Medicine; Abha R. Gupta, Child Study Center, Department of Pediatrics, Yale University School of Medicine; Dietrich Matern, Biochemical Genetics Laboratory, Department of Laboratory Medicine and Pathology, Mayo Clinic; Stacy Gabriel, Broad Institute of Harvard and Massachusetts Institute of Technology; Larry Sweetman, Institute of Metabolic Disease, Baylor Research Institute; Yasmeen Rahimi and Robert A. Harris, Roudebush VA Medical Center and Department of Biochemistry and Molecular Biology, Indiana University School of Medicine.
Funding for this research came, in part, from the National Institutes of Health (grants P1HD070494, R01NS048453, P30NS047101, RC2MH089956, K08MH087639, T32MH018268, U54HG003067), the Center for Inherited Disease Research, the Simons Foundation Research Initiative, Veterans Administration Merit Award, the German Research Foundation, the American Academy of Child and Adolescent Psychiatry Pilot Research Award/Elaine Schlosser Lewis Fund and the American Psychiatric Association/Lilly Research Fellowship.