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Purdue receives $105M to lead earthquake engineering network

admin — Fri, 11 Sep 2009 14:13:57 +0000

WEST LAFAYETTE, Ind. — Advancing research and education to reduce the devastation and loss of human life from earthquakes and tsunamis is the goal of a new center at Purdue University.

HUBzero is a new way for scientists and engineers to publish and share information. The latest hub will be used to study the causes and effects of earthquakes for the Network for Earthquake Engineering Simulation, or NEES. This hub joins others focused on topics such as nanotechnology, microelectromechanical systems, pharmaceutical products, cancer care, assistive technologies for people with disabilities, heat-transfer issues in engineering, and several others. New hubs are being created at a rate of about one per month. (Purdue University image/Michele Rund and Steve Tally)

The National Science Foundation awarded $105 million to a Purdue-led team to spearhead a center that will serve as headquarters for the operations of the George E. Brown, Jr. Network for Earthquake Engineering Simulation, or NEES. Submitted through the Cyber Center in Purdue’s Discovery Park, the grant spans five years and is the largest in the university’s history.

Purdue will connect 14 NEES research equipment sites and the earthquake engineering community through groundbreaking cyberinfrastructure, education and outreach efforts. Purdue’s center is expected to begin operations on Oct. 1, and will be housed in the university’s Discovery Learning Research Center in Discovery Park.

“I was delighted to learn that Purdue has the opportunity to lead this consortium of first-rate research universities,” said Purdue President France A. Córdova, who serves on the National Science Board, the governing board for the NSF, but was excused from deliberations on the award. “I’ve seen firsthand how devastating an earthquake can be not only to buildings, highways and the infrastructure of a city, but also to families, the community and people’s sense of security.

“Purdue’s depth of knowledge in earthquake engineering, innovative high-performance computing experts, education professionals and outstanding interdisciplinary research abilities allow the university to make great contributions to this area. The universities and institutions participating have had great individual successes, and we hope to bring them together to create a whole that is even greater than the sum of its parts.”

In the past decade, 124 major earthquakes have occurred throughout the world, according to the U.S. Geological Survey. Major earthquakes are generally accepted to register a magnitude in excess of 7 on the Richter scale and inflict serious damage, including the collapse of buildings and bridges, over a large area.

The organization estimates that earthquakes were responsible for 463,959 deaths in the past decade.

The Purdue-led NEEScomm Center, which stands for NEES Community and Communications, includes partners from the University of Washington at Seattle, University of Texas at Austin, University of Kansas at Lawrence, San Jose State University, the University of Florida at Gainsville, University of Michigan at Ann Arbor and Fermi National Accelerator Laboratory.

The center will help researchers share information and equipment to enable research and innovation in earthquake and tsunami loss reduction, create an educated work force in hazard mitigation, and conduct broader outreach and lifelong learning activities, said Julio Ramirez, the project’s principal investigator and a professor of civil engineering.

“Recent events have highlighted the importance of earthquake engineering for the United States and the world,” said Ramirez, who also will serve as the center’s director. “In China last year, tens of thousands of people perished as entire cities came down. The earthquake caused a tremendous financial burden in terms of rebuilding the civil infrastructure, but more than that, a high percentage of those who died were children – the future of a nation.”

Building codes and earthquake preparedness have improved in recent years, but even cities that lead in incorporating the latest safety features are at risk for serious damage, he said.

“Even in Los Angeles, a relatively young city in the global perspective, the building inventory includes structures that were built before buildings were engineered to mitigate earthquake hazard,” Ramirez said. “Earthquake design provisions have changed rapidly and substantially since 1980.”

Older cities and those in developing countries are likely to have the most buildings vulnerable to earthquakes and face the highest risk for damage and loss of lives, he said.

Forbes magazine cited a 2001 study by GeoHazards International that estimated the number of lives that would be lost if different cities experienced a magnitude 6 or higher earthquake. The study evaluated cities in Asia and the Americas. Kathmandu, Nepal, topped the list, followed by Istanbul, Turkey; Delhi, India; Quito, Ecuador; Manila, Philippines; and Islambad, Pakistan. All of the cities were estimated to face tens of thousands of fatalities if an earthquake struck.

The Purdue-based center will lead, manage, operate and maintain NEES. Through the NEES network, researchers from the United States and abroad conduct experiments and simulations of the ways buildings, bridges, utility systems and different materials perform during seismic events. Earthquake engineers will use this information to develop better and more cost-effective ways of reducing earthquake damage through improved materials, construction techniques and monitoring tools, Ramirez said.

The center’s education, outreach and training initiatives will use engineering education research to construct next-generation learning experiences that can be disseminated globally, he said. A team of engineering educators and technology specialists will develop the NEES Academy, a state-of-the-art virtual institution for cyber-enabled learning. The academy will help preK-12 teachers develop student interest in, and awareness of, science, mathematics, engineering and technology and will support undergraduate and graduate students engaging in research.

“The center will bring world-class education to any place in the world that has access to broadband Internet,” Ramirez said. “It will enable colleges and universities that don’t have the educational resources of Purdue to access the facilities, equipment, simulations and teaching tools of the participating institutions.”

Joy M. Pauschke, NEES program director at the National Science Foundation, said NEES is an integral part of the U.S. National Earthquake Hazards Reduction Program to support basic research to discover new knowledge, innovation and technologies for earthquake and tsunami loss reduction for the nation.

“During the first five years of operations, the unique NEES experimental capabilities and the extraordinarily strong user support from facility staff have enabled landmark testing and comprehensive experimental data capture for modeling seismic performance that was not possible before NEES,” Pauschke said. “Through Purdue’s leadership, the NEES experimental facilities, NEEShub and NEES Academy will provide world-class resources for earthquake engineering researchers, educators, students and practitioners not only in the United States, but globally.”

A cornerstone of the center is the development of information technology components that allow for new forms of collaboration and cooperation, said Rudolf Eigenmann, co-principal investigator and professor of electrical and computer engineering.

The NEEScomm Center will be a collaborative space and science hub where scientists and engineers can run scientific models and “what if?” scenarios. Hubs, which were first developed at Purdue, allow researchers to run models using a simple Web interface. The hub connects with supercomputing resources on the NSF’s TeraGrid and the national DiaGrid, which allow researchers to run their experiments without having to request time on a supercomputer.

Rudolf Eigenmann, professor of electrical and computer engineering, stands in front of screens displaying the prototype cyberinfrastructure for NEEScomm. The National Science Foundation awarded $105 million to a Purdue-led team to spearhead a center that will serve as headquarters for the operations of the George E. Brown, Jr. Network for Earthquake Engineering Simulation. Eigenmann is a co-principal investigator on the project. (Purdue News Service photo/Andrew Hancock)

“A critical and often difficult component of sharing data to advance research is making the findings of others easy to access and use,” Eigenmann said. “The HUBzero technology will allow for someone to simply go to a Web site and instantly be able to view data or run a simulation. It will eliminate the need to first download and install an application to view the data and then spend time downloading a large volume of data before beginning work.”

The cyberinfrastructure to be deployed by the NEEScomm Center is powered using HUBzero technology, which was originally created by researchers at Purdue University to support nanoHUB.org, a site for researchers studying nanotechnology. Currently there are nine other hubs online in science, engineering and medicine, and 12 more are expected to be online within a year, including the new NEEShub.

Ellen Rathje, professor of geotechnical engineering at the University of Texas at Austin and co-principal investigator of the project, said another key advantage of NEEShub is its data presentation capabilities.

“The new information technology created will enable research to take place that couldn’t be done before,” Rathje said. “Data will be presented in an easily searchable and usable format, like a virtual lab notebook, that will give experiments a longer life as researchers reuse existing data to run their own analysis and find new insights. It’s sort of like Facebook for scientists, but instead of posting vacation photos we’re posting research results.”

In addition to Ramirez and Eigenmann, Purdue University project co-principal investigators include Thomas Hacker, assistant professor of computer and information technology; Sean Brophy, assistant professor of engineering education; and Saurabh Bagchi, associate professor of electrical and computer engineering.

In addition, assistant professors of civil engineering Santiago Pujol and Ayhan Irfanoglu provide the team with earthquake engineering expertise in information technology matters of tele-operation and data management.

Project co-principal investigator Barbara Fossum, former managing director of Purdue’s Cyber Center, will serve as the center’s deputy director, and Dawn Weisman, former managing director of Purdue’s PRISM: National Nuclear Security Administration Center for Prediction of Reliability, Integrity and Survivability of Microsystems, will serve as information technology director.

Co-principal investigators Brophy and Thalia Anagnos from San Jose State University will co-lead the center’s education, outreach and training initiatives.

Fossum said the center will manage the operations of the network and engage the equipment sites to effectively carry out program initiatives.

“The United States has invested close to $300 million to commission and enable the equipment sites, and there are over 100 projects currently under way,” she said. “It is a resource for the nation and we want to help realize its full potential by sharing the unique resources and programs at each site across the network and with those interested in mitigating earthquake hazards throughout the world.”

The center will create more than 20 full-time positions and five graduate student positions at Purdue for Web application developers, software engineers, and research scientists and engineers.

The NEES equipment sites include Oregon State University; University of Nevada, Reno; University of California, Davis; University of California, Berkeley; University of California, Santa Barbara; University of California at Los Angeles; University of California at San Diego; University of Texas, Austin; University of Minnesota; University of Illinois, Urbana; University at Buffalo-SUNY; Cornell University; Rensselaer Polytechnic Institute; and Lehigh University.

NEES began development in 2000 and is a shared national network of 14 state-of-the-art earthquake engineering and tsunami experimental facilities at universities across the United States. It includes collaborative tools, a centralized data repository and earthquake simulation software.

Estrogen supplements not as effective as claimed

admin — Thu, 10 Sep 2009 18:28:07 +0000

WEST LAFAYETTE, Ind. — Dietary supplements claiming to help postmenopausal women with bone health may not be doing what they say, according to new research from Purdue University.

Women who are menopausal or postmenopausal produce less estrogen, and that leads to bone loss. More than 2 million women in the United States reach menopause each year, according to the National Women's Health Resource Center.

“We found that some plant-derived isoflavones have a modest effect on suppressing bone loss during post-menopause, but more concerning is many dietary supplements that claim to have the power of estrogen do not,” said Connie Weaver, distinguished professor of foods and nutrition. “It’s buyer beware. Some of the supplements in our study claimed to be substitutes for estrogen, yet they weren’t effective at all or weren’t as effective as some of the current treatments for osteoporosis.”

Estrogen hormone replacement therapy was the traditional treatment, but it is no longer recommended for the long term because of links to stroke, embolism and breast cancer. Some individuals have harmful side effects with long-term use of bisphosphonates, the current main class of osteoporosis treatment drugs.

“This is a reminder that it’s better to build up a good healthy skeleton than to rely on a drug to fix it later,” Weaver said. “Healthy bones can be maintained by a good diet that is rich in calcium and regular exercise that includes strength training.”

Weaver, who also is co-director of the Botanicals Research Center for Age Related Diseases, and her team looked at four popular isoflavones: soy cotyledon, soy germ, red clover and kudzu. These plant-derived phytoestrogens are claimed to protect bone health from estrogen loss, which can lead to osteoporosis and even fractures.

The researchers compared the four isoflavones to a traditional bisphosphonate treatment, risedronate and estrogen plus progesterone. These traditional therapies decreased bone loss 22 percent to 24 percent, but only soy isoflavones from the cotyledon and germ significantly decreased bone loss by 9 percent and 5 percent, respectively. The findings are available online and will be published in the October edition of the Journal of Clinical Endocrinology and Metabolism.

The findings also indicate that the soy cotyledon was more effective because of its higher genistein content. Weaver’s team is currently evaluating the role of genistein more closely.

“Before, we might have assumed that any isoflavone was equally effective, but we found that for a supplement to work it was because of the genistein content specifically,” she said.

This work was funded by the National Institutes of Health and supplements were supplied by the dietary and health companies Cognis, Frutarom and Novagen. Weaver also is on the advisory board of Pharmative and Wyeth Global Nutrition. The Botanicals Research Center for Age Related Diseases is a partnership between Purdue and the University of Alabama-Birmingham.

Tropical storms sustain over wet land, fizzle out over dry ground

admin — Wed, 26 Aug 2009 15:32:05 +0000

WEST LAFAYETTE, Ind. — If it has already rained, it’s going to continue to pour, according to a Purdue University study of how ocean-origin storms behave when they come ashore.

Storm clouds gather as India braces for a storm during monsoon season.

More than 30 years of monsoon data from India showed that ground moisture where the storms make landfall is a major indicator of what the storm will do from there. If the ground is wet, the storm is likely to sustain, while dry conditions should calm the storm.

“Once a storm comes overland, it was unclear whether it would stall, accelerate or fizzle out,” said Dev Niyogi, Indiana state climatologist and associate professor of agronomy and earth and atmospheric sciences. “We found that whether a storm becomes more intense or causes heavy rains could depend on the land conditions – something we’d not considered. Thus far we’ve looked at these storms based mainly on ocean conditions or upper atmosphere.”

Niyogi said tropical storms gain their strength from warm ocean water evaporation.

“The same phenomenon – the evaporation from the ocean that sustains the storms – could be the same phenomenon that sustains that storm over land with moisture in the soil,” he said. “The storm will have more moisture and energy available over wet soil than dry.”

Niyogi’s team’s findings were published in the August edition of the journal Geophysical Research Letters.

Storm data fed into a model showed that higher levels of ground moisture would sustain Indian monsoon depressions. The model’s prediction was proven when compared to ground conditions for 125 Indian monsoons over 33 years, where storms sustained when the ground was wet at landfall.

Knowing the sustainability of a storm could lead to better predictions on flooding and damage inland before a monsoon or a hurricane makes landfall.

“We think the physics is such that we could see similar results more broadly, such as in the United States,” Niyogi said.

The National Science Foundation and NASA funded the research. The Purdue led-team also consisted of researchers from the National Center for Atmospheric Research, NASA-GSFC/ESSIC, the University of Georgia, the Indian Space Research Organization and the Indian Institute of Technology Delhi.

Niyogi said the next step is to use the model and ground moisture data to test these theories for hurricanes in the United States.

Personality traits associated with stress and worry can be hazardous to your health

admin — Fri, 21 Aug 2009 01:16:33 +0000

WEST LAFAYETTE, Ind. — Personality traits associated with chronic worrying can lead to earlier death, at least in part because these people are more likely to engage in unhealthy behaviors, such as smoking, according to research from Purdue University.

The study found that people who have worrying tendencies or stress easily are more likely to self-medicate with hazardous behaviors like smoking or excessive consumption of alcohol.

“Research shows that higher levels of neuroticism can lead to earlier mortality, and we wanted to know why,” said Daniel K. Mroczek, a professor of child development and family studies. “We found that having worrying tendencies or being the kind of person who stresses easily is likely to lead to bad behaviors like smoking and, therefore, raise the mortality rate.

“This work is a reminder that high levels of some personality traits can be hazardous to one’s physical health.”

Chronic worrying, anxiety and being prone to depression are key aspects of the personality trait of neuroticism. In this study, the researchers looked at how smoking and heavy drinking are associated with the trait. A person with high neuroticism is likely to experience anxiety or depression and may self-medicate with tobacco, alcohol or drugs as a coping mechanism.

They found that smoking accounted for about 25 percent to 40 percent of the association between high neuroticism and mortality. The other 60 percent is unexplained, but possibly attributed to biological factors or other environmental issues that neurotic individuals experience, Mroczek said.

The researchers analyzed data of 1,788 men and their smoking behavior and personality traits over a 30-year period from 1975 to 2005. The data was part of the VA Normative Aging Study, which is a long-term study of aging men based at the Boston VA Outpatient Clinic.

Mroczek and his co-authors, Avron Spiro III and Nicholas A. Turiano, published their findings in this month’s Journal of Research in Personality.

A better understanding of the bridge between personality traits and physical health can perhaps help clinicians improve intervention and prevention programs, Mroczek said.

“For example, programs that target people high in neuroticism may get bigger bang for the buck than more widespread outreach efforts,” he said. “It also may be possible to use personality traits to identify people who, because of their predispositions, are at risk for engaging in poor health behaviors such as smoking or excessive drinking.”

The National Institute on Aging and the U.S. Department of Veterans Affairs supported this work.

Study of 16 developing countries shows climate change could deepen poverty

admin — Fri, 21 Aug 2009 00:18:13 +0000

WEST LAFAYETTE, Ind. — Urban workers could suffer most from climate change as the cost of food drives them into poverty, according to a new study that quantifies the effects of climate on the world’s poor populations.

These maps show projected changes in frequency and magnitude of climate extremes. A Purdue team found that the occurrence and magnitude of what are currently the 30-year-maximum values for wet, dry and hot extremes are projected to substantially increase for much of the world. (Diffenbaugh lab image)

A team led by Purdue University researchers examined the potential economic influence of adverse climate events, such as heat waves, drought and heavy rains, on those in 16 developing countries. Urban workers in Bangladesh, Mexico and Zambia were found to be the most at risk.

“Extreme weather affects agricultural productivity and can raise the price of staple foods, such as grains, that are important to poor households in developing countries,” said Noah Diffenbaugh, the associate professor of earth and atmospheric sciences and interim director of Purdue’s Climate Change Research Center who co-led the study. “Studies have shown global warming will likely increase the frequency and intensity of heat waves, drought and floods in many areas. It is important to understand which socioeconomic groups and countries could see changes in poverty rates in order to make informed policy decisions.”

The team used data from the late 20th century and projections for the late 21st century to develop a framework that examined extreme climate events, comparable shocks to grain production and the impact on the number of impoverished people in each country.

Thomas Hertel, a distinguished professor of agricultural economics and co-leader of the study, said that although urban workers only contribute modestly to total poverty rates in the sample countries, they are the most vulnerable group to changes in grains production.

This graph shows the percentage of the population in poverty in 2001 and the change in poverty due to extreme climate for the sample countries. A Purdue team found that urban workers could suffer the most from climate change as the cost of food drives them into poverty. (Hertel lab image)

“Food is a major expenditure for the poor and, while those who work in agriculture would have some benefit from higher grains prices, the urban poor would only get the negative effects,” said Hertel, who also is executive director of Purdue’s Center for Global Trade Analysis. “This is an important finding given that the United Nations projects a continuing shift in population concentrations from rural to urban areas in virtually all of these developing countries.”

With nearly 1 billion of the world’s poor living on less than $1 a day, extreme events can have a devastating impact, he said.

“Bangladesh, Mexico and Zambia showed the greatest percentage of the population entering poverty in the wake of extreme drought, with an additional 1.4 percent, 1.8 percent and 4.6 percent of their populations being impoverished by future climate extremes, respectively,” Hertel said. “This translates to an additional 1.8 million people impoverished per country for Bangladesh and Mexico and an additional half million people in Zambia.”

A paper detailing the work will be published in Thursday’s (Aug. 20) issue of Environmental Research Letters. In addition to Diffenbaugh and Hertel, Syud Amer Ahmed, a recent Purdue graduate and a member of the development research group for The World Bank, co-authored the paper. The World Bank’s Trust Fund for Environmentally and Socially Sustainable Development funded the research.

The team identified the maximum rainfall, drought and heat wave for the 30-year periods of 1971-2000 and 2071-2100 and then compared the maximums for the two time periods.

Factory workers in Bangladesh. (Photo copyright the World Bank/Thomas Sennett)

The global climate model experiments developed by the Intergovernmental Panel on Climate Change, or IPCC, were used for the future projections of extreme events. The team used an IPCC scenario that has greenhouse gas emissions continuing to follow the current trend, Diffenbaugh said.

“The occurrence and magnitude of what are currently the 30-year-maximum values for wet, dry and hot extremes are projected to substantially increase for much of the world,” he said. “Heat waves and drought in the Mediterranean showed a potential 2700 percent and 800 percent increase in occurrence, respectively, and extreme rainfall in Southeast Asia was projected to potentially increase by 900 percent.”

In addition, Southeast Asia showed a projected 40 percent increase in the magnitude of the worst rainfall; central Africa showed a projected 1000 percent increase in the magnitude of the worst heat wave; and the Mediterranean showed a projected 60 percent increase in the worst drought.

A statistical analysis was used to determine grain productivity shocks that would correspond in magnitude to the climate extremes, and then the economic impact of the supply shock was determined. Future predicted extreme climate events were compared to historical agricultural productivity extremes in order to assess the likely impact on agricultural production, prices and wages. Because the projected changes in extreme rainfall and heat wave events were too large for the current model to accept, only the extreme drought events were incorporated into the economic projections, making the projected poverty impacts a conservative estimate, he said.

To assess the potential economic impact of a given change in wages and grains prices, the team used data from each country’s household survey. The estimates of likely wage and price changes following an extreme climate event were obtained from a global trade model, called the Global Trade Analysis Project, or GTAP, which is maintained by Purdue’s agricultural economics department.

Purdue’s GTAP framework is supported by an international consortium of 27 national and international agencies and is used by a network of 6,500 researchers in 140 countries.

Large reductions in grains productivity due to extreme climate events are supported by historical data. In 1991 grains productivity in Malawi and Zambia declined by about 50 percent when southern Africa experienced a severe drought.

Diffenbaugh said this is an initial quantification of how poverty is tied to climate fluctuations, and the team is working to improve the modeling and analysis system in order to enable more comprehensive assessments of the link between climate volatility and poverty vulnerability.

New nanolaser key to future optical computers and technologies

admin — Mon, 17 Aug 2009 21:44:19 +0000

WEST LAFAYETTE, Ind. — Researchers have created the tiniest laser since its invention nearly 50 years ago, paving the way for a host of innovations, including superfast computers that use light instead of electrons to process information, advanced sensors and imaging.

Researchers have created the tiniest laser since its invention nearly 50 years ago. Because the new device, called a 'spaser', is the first of its kind to emit visible light, it represents a critical component for possible future technologies based on 'nanophotonic' circuitry. The color diagram (a) shows the nanolaser's design: a gold core surrounded by a glasslike shell filled with green dye. Scanning electron microscope images (b and c) show that the gold core and the thickness of the silica shell were about 14 nanometers and 15 nanometers, respectively. A simulation of the SPASER (d) shows the device emitting visible light with a wavelength of 525 nanometers. (Birck Nanotechnology Center, Purdue University)

Because the new device, called a “spaser,” is the first of its kind to emit visible light, it represents a critical component for possible future technologies based on “nanophotonic” circuitry, said Vladimir Shalaev, the Robert and Anne Burnett Professor of Electrical and Computer Engineering at Purdue University.

Such circuits will require a laser-light source, but current lasers can’t be made small enough to integrate them into electronic chips. Now researchers have overcome this obstacle, harnessing clouds of electrons called “surface plasmons,” instead of the photons that make up light, to create the tiny spasers.

Findings are detailed in a paper appearing online in the journal Nature that reports on work conducted by researchers at Purdue, Norfolk State University and Cornell University.

Nanophotonics may usher in a host of radical advances, including powerful “hyperlenses” resulting in sensors and microscopes 10 times more powerful than today’s and able to see objects as small as DNA; computers and consumer electronics that use light instead of electronic signals to process information; and more efficient solar collectors.

“Here, we have demonstrated the feasibility of the most critical component – the nanolaser – essential for nanophotonics to become a practical technology,” Shalaev said.

The “spaser-based nanolasers” created in the research were spheres 44 nanometers, or billionths of a meter, in diameter – more than 1 million could fit inside a red blood cell. The spheres were fabricated at Cornell, with Norfolk State and Purdue performing the optical characterization needed to determine whether the devices behave as lasers.

The findings confirm work by physicists David Bergman at Tel Aviv University and Mark Stockman at Georgia State University, who first proposed the spaser concept in 2003.

“This work represents an important milestone that may prove to be the start of a revolution in nanophotonics, with applications in imaging and sensing at a scale that is much smaller than the wavelength of visible light,” said Timothy D. Sands, the Mary Jo and Robert L. Kirk Director of the Birck Nanotechnology Center in Purdue’s Discovery Park.

The spasers contain a gold core surrounded by a glasslike shell filled with green dye. When a light was shined on the spheres, plasmons generated by the gold core were amplified by the dye. The plasmons were then converted to photons of visible light, which was emitted as a laser.

Spaser stands for surface plasmon amplification by stimulated emission of radiation. To act like lasers, they require a “feedback system” that causes the surface plasmons to oscillate back and forth so that they gain power and can be emitted as light. Conventional lasers are limited in how small they can be made because this feedback component for photons, called an optical resonator, must be at least half the size of the wavelength of laser light.

The researchers, however, have overcome this hurdle by using not photons but surface plasmons, which enabled them to create a resonator 44 nanometers in diameter, or less than one-tenth the size of the 530-nanometer wavelength emitted by the spaser.

“It’s fitting that we have realized a breakthrough in laser technology as we are getting ready to celebrate the 50th anniversary of the invention of the laser,” Shalaev said.

The first working laser was demonstrated in 1960.

The research was conducted by Norfolk State researchers Mikhail A. Noginov, Guohua Zhu and Akeisha M. Belgrave; Purdue researchers Reuben M. Bakker, Shalaev and Evgenii E. Narimanov; and Cornell researchers Samantha Stout, Erik Herz, Teeraporn Suteewong and Ulrich B. Wiesner.

Future work may involve creating a spaser-based nanolaser that uses an electrical source instead of a light source, which would make them more practical for computer and electronics applications.

The work was funded by the National Science Foundation and U.S. Army Research Office and is affiliated with the Birck Nanotechnology Center, the Center for Materials Research at Norfolk State, and Cornell’s Materials Science and Engineering Department.

Purdue researchers create prostate cancer ‘homing device’ for drug delivery

admin — Tue, 07 Jul 2009 15:06:52 +0000

WEST LAFAYETTE, Ind. — A new prostate cancer “homing device” could improve detection and allow for the first targeted treatment of the disease.

A team of Purdue University researchers has synthesized a molecule that finds and penetrates prostate cancer cells and has created imaging agents and therapeutic drugs that can link to the molecule and be carried with it as cargo.

A radioimaging application used for body scans is expected to enter clinical trials this fall, and an optical imaging application used to measure prostate cancer cells in blood samples is already in clinical trials.

Philip Low, the Ralph C. Corley Distinguished Professor of Biochemistry who led the team, said a targeted treatment could be much more effective in treating cancer and would greatly reduce the harmful side effects associated with current treatments.

This image depicts transporter molecules carrying therapeutic drugs to PSMA targets on a prostate cancer cell. A Purdue research team designed a molecule that finds and penetrates prostate cancer cells and can transport drugs or imaging agents into the cell. (Image courtesy of Low laboratory)

“Currently none of the drugs available to treat prostate cancer are targeted, which means they go everywhere in the body as opposed to only the tumor, and so are quite toxic for the patient,” said Low, who is a member of the Purdue Cancer Center. “By being able to target only the cancer cells, we could eliminate toxic side effects of treatments. In addition, the ability to target only the cancer cells can greatly improve imaging of the cancer to diagnose the disease, determine if it has spread or is responding to treatment.”

Prostate cancer is the most common cancer, other than skin cancers, and is the second leading cause of cancer death in American men, according to the American Cancer Society. It is estimated that about 192,280 new cases will be diagnosed and 27,360 men will die of prostate cancer in the United States this year.

The molecule Low’s team created attaches to prostate-specific membrane antigen, or PSMA, a protein that is found on the membrane of more than 90 percent of all prostate cancers. It also is found on the blood vessels of most solid tumors and could provide a way to cut off the tumor blood supply, Low said.

“A lot of new drugs are being designed to destroy the vasculature of solid tumors, and, if they could be linked to this new targeting molecule, we could have a two-pronged attack for prostate cancer,” he said. “We could not only kill the prostate cancer cells directly, we could also destroy the vasculature that feeds the tumors.”

There also is potential for the targeting molecule to be used to attack the vasculature of solid tumors of other types of cancers, Low said.

Two papers detailing the work of the Purdue team were published in the June 1 issue of Molecular Pharmaceutics. Endocyte Inc. funded the work.

The team’s animal study data shows an ability to eliminate human prostate cancer cells in mice with no evidence of collateral toxicity in normal tissue.

Sumith Kularatne, a graduate student in Purdue’s chemistry department and first author of both papers, compared the targeting molecule to a homing device.

“The molecule acts like a homing device for prostate cancer,” he said. “PSMA, which is found only on prostate cancer cells and tumor blood vessels, acts as the homing signal that the molecule targets. The molecule and its cargo go only to cancerous tissue, leaving healthy tissue unharmed.”

Once the molecule reaches the PSMA protein, it binds to it. The molecule is designed with a specific shape that fits with the protein like a key to a lock, Kularatne said. The molecule and its cargo are then carried inside the cell with the protein as it goes through its normal cycle.

In 1995 Low developed a similar method to infiltrate cancer cells by attaching treatments to the vitamin folate, which many cancers rapidly consume. This method provided a “Trojan Horse” entry of large treatment molecules that otherwise would not be able to enter cancer cells.

Low was inspired to find a similar way to target prostate cancer, which does not have the same appetite for folate, he said.

A clinical trial of the radioimaging application is expected to begin at the Indiana University Medical Center in the fall through a collaboration between the Purdue Cancer Center and the Indiana University Cancer Center with additional support from Endocyte Inc.

A radioimaging agent linked to the targeting molecule will be injected into prostate cancer patients and pictures will be taken using a special camera that detects radioactivity. The pictures show where the cancer is present to help doctors determine if it has metastasized, or spread, to any other areas of the body. It also will help doctors decide on the best course of treatment, Low said.

There is currently only one radioimaging agent for prostate cancer approved by the Food and Drug Administration.

“The current imaging capabilities available for prostate cancer are very poor,” Low said. “The existing imaging agent is limited because of its large size, which is difficult to get into a solid tumor. Also it seeks out a target located inside the cancer cell and is only able to mark injured cells that are falling apart as opposed to actively growing cancer cells.”

The targeting molecule and radioimaging agent combination designed by Low’s group is more than 150 times smaller than the existing agent and has much easier penetration through a solid tumor to reach all of the cells inside, he said. It also has the advantage of targeting an area of PSMA exposed on the outside of cancer cells.

Already in clinical trials is an optical imaging application that involves attaching a fluorescent dye to the targeting molecule and mixing it with a patient’s blood sample. Circulating prostate cancer cells in the sample fluoresce and are easily measured to help in diagnosing patients with prostate cancer. Researchers also are investigating whether this could be used to evaluate a patient’s response to therapy, Low said.

Low’s research group modeled the targeting molecule after a naturally occurring molecule that strongly binds to PSMA, called DUPA. Several alterations were necessary to create a molecule that fit the needs of a homing device and delivery vehicle, Kularatne said. The team created an area on the molecule that would link to various imaging or therapeutic agents to bring them along as cargo and created a spacer that would stretch the molecule so that its cargo would not keep it from properly fitting into the binding site. The spacer also was designed to improve binding of the targeting molecule to PSMA.

In addition to Low and Kularatne, co-authors of the papers include Endocyte researchers Kevin Wang and Hari-Krishna R. Santhapuram, graduate student in medicinal chemistry Zhigang Zhou, graduate student in chemistry Jun Yang, and professor of medicinal chemistry and molecular pharmacology Carol B. Post.

Low is the chief science officer for Endocyte, a Purdue Research Park-based company that develops receptor-targeted therapeutics for the treatment of cancer and autoimmune diseases. Endocyte holds the license to many of Low’s drug-targeting technologies.

Participants for Purdue’s mini-Camp Calcium sought

admin — Sat, 06 Jun 2009 01:18:42 +0000

WEST LAFAYETTE, Ind. — Girls ages 10-12 are being recruited to participate in a mini-Camp Calcium at Purdue University.

The camp will include three clinical campus visits, six weeks apart. For three weeks before each campus visit, participants will consume a fiber product in a yogurt-like drink.

During a previous Camp Calcium, Technician Leslie Ann Hawrysz, clinical research coordinator in foods and nutrition at Purdue, conducted a bone density scan on a student participating in Camp Calcium. The study ultimately concluded too much salt in the diet reduces bone density in both African-American and Caucasian adolescent girls. (Purdue file photo/Richard Myers-Walls.)

Participants will then stay on campus for two days to complete a calcium absorption test, blood collections, physical fitness tests and bone density measurements.

A minimum three-week “wash-out” period will follow the campus visit before beginning the next study treatment phase.

The girls will be paid for each study phase completed.

Eligibility requirements include a healthy weight, pre-menarche status, no broken bones in the last six months and no medications that influence calcium absorption.

Registration deadline is June 6. For more information about the study or schedule, or to receive an application packet, contact Berdine Martin at 1-800-830-0175, 765-494-6559 or fnbone@purdue.edu

Researchers will study the effect of added fiber on the absorption of calcium in dairy products in preteen girls.

During adolescence, maximum bone growth occurs and a high percentage of calcium is taken into the bone. Purdue’s Department of Foods and Nutrition is studying dietary factors that influence calcium absorption and bone health. Previous studies in adults have shown a positive effect of a particular kind of fiber called galacto-oligosaccharide on calcium absorption. Since maximum bone strength is achieved in adolescence, this short study will be studying preteens.

Speech perception study looking for subjects

admin — Thu, 29 Jan 2009 17:30:48 +0000

WEST LAFAYETTE, Ind. — A Purdue University researcher is looking for adults to participate in a speech perception study in the Department of Speech, Language and Hearing Sciences.

Participants will participate in a listening session that is one to three hours, and the compensation is $10 per hour. People interested in participating must be 18 years or older, be native speakers of American English, have normal hearing and normal or corrected-to-normal vision.

Karen Iler Kirk, professor of speech, language and hearing sciences, is leading the study. To participate, or for more information on the study, contact Lindsay Prusick, a graduate research assistant, at (765) 494-0948 or lprusick@purdue.edu

The study is funded by the National Institutes of Health. The Department of Speech, Languages and Hearing Sciences is housed in the College of Liberal Arts.

Speech and hearing study looking for subjects

admin — Thu, 15 Jan 2009 03:38:14 +0000

WEST LAFAYETTE, Ind. — A Purdue University researcher is seeking adults to participate in a listening study in the Department of Speech, Language and Hearing Sciences.

Karen Iler Kirk, professor of speech, language and hearing sciences, is leading the study. Participants will participate in four sessions, with each session lasting 60-90 minutes. Hearing and vision screenings will be completed during the first visit. Those who pass the screenings will be asked to identify voices while listening to sentences spoken by several different talkers.

People interested in participating must be ages 18-65, have no reported speech or hearing difficulties, have normal or corrected-to-normal vision, and be a native speaker of general American English. Compensation is $40 upon completion of four sessions.

To participate, or for more information on the study, contact Vidya Krull, a research assistant, at vganesh@purdue.edu .

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