First DNA-based Reconstruction of the Giant Extinct Moa Bird
Scientists have performed the first DNA-based reconstruction of the giant extinct moa bird, using prehistoric feathers recovered from caves and rock shelters in New Zealand.
Researchers from the University of Adelaide and Landcare Research in New Zealand have identified four different moa species after retrieving ancient DNA from moa feathers believed to be at least 2500 years old.
The giant birds – measuring up to 2.5 metres and weighing 250 kilograms – were the dominant animals in New Zealand’s pre-human environment but were quickly exterminated after the arrival of the Maori around 1280AD.
PhD student Nicolas Rawlence from the University’s Australian Centre for Ancient DNA says until now, the scientific community has not known what the 10 different species of moa looked like. ”By using ancient DNA we have been able to connect feathers to four different moa species,” he says.
The researchers compared the feathers to others found in the sediments from red-crowned parakeets that are still living today, determining they had not faded or changed in colour. They then reconstructed the appearance of the stout-legged moa, heavy-footed moa, upland moa and the South Island giant moa.
Their findings were published today in the Proceedings of the Royal Society of London Series B.
“The surprising thing is that while many of the species had a similar, relatively plain brown plumage for camouflage, some had white-tipped feathers to create a speckled appearance,” Mr Rawlence says.
A co-author of the study, Dr Jamie Wood from Landcare Research, says it is likely that the drab colouring was driven by selection to avoid predation by the extinct Haast’s eagle, the largest and most powerful eagle in the world.
The research team also demonstrated that it is possible to retrieve DNA from all parts of the ancient feathers, not just the tip of the quill, as previously thought.
“This important finding opens the way to study DNA from museum bird skins while causing almost no damage to these valuable specimens, just by clipping a small part of a single feather,” says Dr Kyle Armstrong from the Australian Centre for Ancient DNA (ACAD).
ACAD Director Professor Alan Cooper says this finding suggests it may be possible to reconstruct the appearance of other extinct birds using feathers from fossil deposits.
“There are so many enigmatic extinct species that it would be great to see ‘clothed’," Professor Cooper says.
Wednesday, July 01, 2009
Wednesday, June 24, 2009
First Direct Visualization of Memory Formation in the Brain
FINDINGS: UCLA and McGill University researchers have, for the first time, “photographed” a memory in the making. The study clarifies one of the ways in which connections in the brain between nerve cells, called synapses, can be changed with experience. The phenomenon is called “synaptic plasticity,” and is the foundation for how we learn and remember. As we learn, the memories are stored in changes in the strength and/or number of synaptic connections between nerve cells in our brain. Long lasting changes in synaptic connections are required for long-term memories, and the persistence of these changes requires new gene expression. This is the first study to use fluorescent imaging to directly visualize protein synthesis at individual synapses during learning related synaptic plasticity.
IMPACT: Understanding how synapses can change with experience is critical to understanding behavioral plasticity, and to understanding diseases in which learning and experience-dependent behaviors are impaired. Such diseases include mental retardation, Alzheimer’s disease, as well as anxiety and mood disorders. It also can elucidate potential strategies for improving normal cognition and behavioral plasticity.
JOURNAL: The research appears in the June 19 edition of the journal Science.
AUTHORS: Senior author Kelsey Martin, associate professor of psychiatry and biological chemistry; Dan Ohtan Wang, Sang Mok Kim, Yali Zhao, Hongik Hwang, Satoru K. Miura, all of UCLA; and Wayne S. Sossin, McGill University.
HOW: The researchers used sensory and motor neurons from the sea slug Aplysia Californica that can form connections in culture. The neurons were stimulated with serotonin, which strengthens the synapses, and allowed them to detect new protein synthesis—the making of a memory— using a “translational reporter,” a fluorescent protein that can be easily detected and tracked.
MORE: This is the first study to directly visualize protein synthesis at individual synapses during a long-lasting form of synaptic plasticity. The studies revealed an exquisite level of control over the specificity of regulation of new protein synthesis. “While this was not really surprising to us given the complexity of information processing in the brain,” said Martin, “visualizing the process of protein synthesis at individual synapses, and beginning to discern the elegance of its regulation, leaves us, as biologists, with a wonderful sense of awe.”
Funding: This study was funded by the National Institutes of Health, the WM Keck Foundation, and the Canadian Institutes of Health Research. The authors report no conflict of interest.
Friday, June 19, 2009
Bacteria Can Plan Ahead
Bacteria can anticipate a future event and prepare for it, according to new research at the Weizmann Institute of Science. In a paper that appeared in the June 17, 2009 issue of Nature, Prof. Yitzhak Pilpel, doctoral student Amir Mitchell, and research associate Dr. Orna Dahan of the Institute’s Molecular Genetics Department, together with Prof. Martin Kupiec and Gal Romano of Tel Aviv University, examined microorganisms living in environments that change in predictable ways. Their findings show that these microorganisms’ genetic networks are hard-wired to “foresee” what comes next in the sequence of events and begin responding to the new state of affairs before its onset.
E. coli bacteria, for instance, which normally cruise harmlessly down the digestive tract, encounter a number of different environments on their way. In particular, they find that one type of sugar – lactose – is invariably followed by a second sugar – maltose – soon afterward. Pilpel and his team in the Molecular Genetics Department checked the bacteria’s genetic response to lactose and found that, in addition to the genes that enable it to digest lactose, the gene network for utilizing maltose was partially activated. When they switched the order of the sugars, giving the bacteria maltose first, there was no corresponding activation of lactose genes, implying that bacteria have naturally “learned” to get ready for a serving of maltose after a lactose appetizer.
Another microorganism that experiences consistent changes is wine yeast. As fermentation progresses, sugar and acidity levels change, alcohol levels rise, and the yeast’s environment heats up. Although the system was somewhat more complicated than that of E. coli, the scientists found that when the wine yeast feel the heat, they begin activating genes for dealing with the stresses of the next stage. Further analysis showed that this anticipation and early response is an evolutionary adaptation that increases the organism’s chances of survival.
Ivan Pavlov first demonstrated this type of adaptive anticipation, known as a conditioned response, in dogs in the 1890s. He trained the dogs to salivate in response to a stimulus by repeatedly ringing a bell before giving them food. In the microorganisms, says Pilpel, “evolution over many generations replaces conditioned learning, but the end result is similar.” “In both evolution and learning,” says Mitchell, “the organism adapts its responses to environmental cues, improving its ability to survive.” Romano: “This is not a generalized stress response, but one that is precisely geared to an anticipated event.” To see whether the microorganisms were truly exhibiting a conditioned response, Pilpel and Mitchell devised a further test for the E. coli based on another of Pavlov’s experiments. When Pavlov stopped giving the dogs food after ringing the bell, the conditioned response faded until they eventually ceased salivating at its sound. The scientists did something similar, using bacteria grown by Dr. Erez Dekel, in the lab of Prof. Uri Alon of the Weizmann Institute’s Molecular Cell Biology Department, in an environment containing the first sugar, lactose, but not following it up with maltose. After several months, the bacteria had evolved to stop activating their maltose genes at the taste of lactose, only turning them on when maltose was actually available.
“This showed us that there is a cost to advanced preparation, but that the benefits to the organism outweigh the costs in the right circumstances,” says Pilpel. What are those circumstances? Based on the experimental evidence, the research team created a sort of cost/benefit model to predict the types of situations in which an organism could increase its chances of survival by evolving to anticipate future events. The researchers are already planning a number of new tests for their model, as well as different avenues of experimentation based on the insights they have gained.
Pilpel and his team believe that genetic conditioned response may be a widespread means of evolutionary adaptation that enhances survival in many organisms – one that may also take place in the cells of higher organisms, including humans. These findings could have practical implications, as well. Genetically engineered microorganisms for fermenting plant materials to produce biofuels, for example, might work more efficiently if they gained the genetic ability to prepare themselves for the next step in the process.
Prof. Yitzhak Pilpel’s research is supported by the Ben May Charitable Trust and Madame Huguette Nazez, Paris, France.
The Weizmann Institute of Science in Rehovot, Israel, is one of the world's top-ranking multidisciplinary research institutions. Noted for its wide-ranging exploration of the natural and exact sciences, the Institute is home to 2,600 scientists, students, technicians, and supporting staff. Institute research efforts include the search for new ways of fighting disease and hunger, examining leading questions in mathematics and computer science, probing the physics of matter and the universe, creating novel materials, and developing new strategies for protecting the environment.
Bacteria can anticipate a future event and prepare for it, according to new research at the Weizmann Institute of Science. In a paper that appeared in the June 17, 2009 issue of Nature, Prof. Yitzhak Pilpel, doctoral student Amir Mitchell, and research associate Dr. Orna Dahan of the Institute’s Molecular Genetics Department, together with Prof. Martin Kupiec and Gal Romano of Tel Aviv University, examined microorganisms living in environments that change in predictable ways. Their findings show that these microorganisms’ genetic networks are hard-wired to “foresee” what comes next in the sequence of events and begin responding to the new state of affairs before its onset.
E. coli bacteria, for instance, which normally cruise harmlessly down the digestive tract, encounter a number of different environments on their way. In particular, they find that one type of sugar – lactose – is invariably followed by a second sugar – maltose – soon afterward. Pilpel and his team in the Molecular Genetics Department checked the bacteria’s genetic response to lactose and found that, in addition to the genes that enable it to digest lactose, the gene network for utilizing maltose was partially activated. When they switched the order of the sugars, giving the bacteria maltose first, there was no corresponding activation of lactose genes, implying that bacteria have naturally “learned” to get ready for a serving of maltose after a lactose appetizer.
Another microorganism that experiences consistent changes is wine yeast. As fermentation progresses, sugar and acidity levels change, alcohol levels rise, and the yeast’s environment heats up. Although the system was somewhat more complicated than that of E. coli, the scientists found that when the wine yeast feel the heat, they begin activating genes for dealing with the stresses of the next stage. Further analysis showed that this anticipation and early response is an evolutionary adaptation that increases the organism’s chances of survival.
Ivan Pavlov first demonstrated this type of adaptive anticipation, known as a conditioned response, in dogs in the 1890s. He trained the dogs to salivate in response to a stimulus by repeatedly ringing a bell before giving them food. In the microorganisms, says Pilpel, “evolution over many generations replaces conditioned learning, but the end result is similar.” “In both evolution and learning,” says Mitchell, “the organism adapts its responses to environmental cues, improving its ability to survive.” Romano: “This is not a generalized stress response, but one that is precisely geared to an anticipated event.” To see whether the microorganisms were truly exhibiting a conditioned response, Pilpel and Mitchell devised a further test for the E. coli based on another of Pavlov’s experiments. When Pavlov stopped giving the dogs food after ringing the bell, the conditioned response faded until they eventually ceased salivating at its sound. The scientists did something similar, using bacteria grown by Dr. Erez Dekel, in the lab of Prof. Uri Alon of the Weizmann Institute’s Molecular Cell Biology Department, in an environment containing the first sugar, lactose, but not following it up with maltose. After several months, the bacteria had evolved to stop activating their maltose genes at the taste of lactose, only turning them on when maltose was actually available.
“This showed us that there is a cost to advanced preparation, but that the benefits to the organism outweigh the costs in the right circumstances,” says Pilpel. What are those circumstances? Based on the experimental evidence, the research team created a sort of cost/benefit model to predict the types of situations in which an organism could increase its chances of survival by evolving to anticipate future events. The researchers are already planning a number of new tests for their model, as well as different avenues of experimentation based on the insights they have gained.
Pilpel and his team believe that genetic conditioned response may be a widespread means of evolutionary adaptation that enhances survival in many organisms – one that may also take place in the cells of higher organisms, including humans. These findings could have practical implications, as well. Genetically engineered microorganisms for fermenting plant materials to produce biofuels, for example, might work more efficiently if they gained the genetic ability to prepare themselves for the next step in the process.
Prof. Yitzhak Pilpel’s research is supported by the Ben May Charitable Trust and Madame Huguette Nazez, Paris, France.
The Weizmann Institute of Science in Rehovot, Israel, is one of the world's top-ranking multidisciplinary research institutions. Noted for its wide-ranging exploration of the natural and exact sciences, the Institute is home to 2,600 scientists, students, technicians, and supporting staff. Institute research efforts include the search for new ways of fighting disease and hunger, examining leading questions in mathematics and computer science, probing the physics of matter and the universe, creating novel materials, and developing new strategies for protecting the environment.
Key Found to How Tumor Cells Invade the Brain in Childhood Cancer
Despite great strides in treating childhood leukemia, a form of the disease called T-cell acute lymphoblastic leukemia (T-ALL) poses special challenges because of the high risk of leukemic cells invading the brain and spinal cord of children who relapse. Now, a new study in the June 18, 2009, issue of the journal Nature by scientists at NYU School of Medicine reveals the molecular agents behind this devastating infiltration of the central nervous system. The finding may lead to new drugs that block these agents and thus lower the risk of relapse.
T-ALL, a blood-borne cancer in which the bone marrow makes too many lymphocytes, or white blood cells, strikes several hundred children and adolescents in the U.S. annually. While greater than 90% percent go into remission through a combination of chemotherapy and radiation, up to one third of this group end up relapsing. These patients are at particular risk for tumor cells to invade the brain and spinal cord, and to prevent this all patients receive chemotherapy injections into the central nervous system and in some cases cranial irradiation—approaches that cause dangerous side effects, including secondary tumors and potentially permanent cognitive and developmental deficits.
“In general, T-cell acute lymphoblastic leukemia is treatable with chemotherapy and radiation,” said Ioannis Aifantis, PhD, associate professor of pathology and co-director of the Cancer Stem Cell Program at the NYU Cancer Institute, who led the new study. “But you have a very high rate of relapse. And after the relapse, it is not treatable because the cancer occurs in tricky places like the central nervous system,” said Dr. Aifantis, who is also an Early Career Scientist at the Howard Hughes Medical Institute.
“We are very proud of this research and very excited about the potential implications for new therapeutic approaches to prevent or reduce the spread of leukemic cells into the central nervous system,” said Vivian S. Lee MD, PhD, MBA, the vice dean for science, senior vice president and chief scientific officer of NYU Langone Medical Center.
In the new study, Dr. Aifantis and his colleagues found that a key protein receptor embedded on the outer surface of leukemic cells is responsible for infiltrating the brain and spinal cord. “What we have found is that leukemic cells over-express this receptor.” said Dr. Aifantis, “If you knock out this receptor, these cells will not go to the brain under any circumstances.”
Previous research had strongly implicated a famous gene regulator called Notch1 in the progression of T-ALL. The Notch1 gene (a mutated version gives fruit flies notched wings) is an oncogene, or cancer-causing gene, in humans. Certain kinds of mutations in this gene have been found in nearly half of all T-ALL patients, and current estimates suggest that the gene’s regulatory influence might be implicated in nearly 90 percent of all T-ALL cases.
For their new study, Dr. Aifantis and his colleagues first introduced overactive forms of Notch1 into mice. As a result, the mice developed leukemia and the leukemic cells efficiently infiltrated the inner layers of the membrane covering the brain. “What happens is that the leukemic cells get into the cerebrospinal fluidthat protects our brain and spine, where they fill up the space and they can affect brain function, either by secreting chemicals and toxic factors or even by simple pressure,” Dr. Aifantis said.
His team then examined an array of other mouse genes to identify candidates that might fall under the regulatory spell of Notch1 to promote the brain and spinal cord infiltration. The screen revealed a promising gene for a protein named CCR7, which is embedded on the surface of lymphocytes. This chemokine receptor, as it’s known, normally senses and responds to small chemical attractants called chemokines, which act like recruitment signals for lymphocytes to converge on a specific site during the body’s response to infection or injury. In leukemia, however, these lymphocytes proliferate abnormally.
CCR7 was already known as a key player in normal lymphocyte migration and as a binding partner of two chemokines named CCL19 and CCL21. Previous studies had implicated these protein interactions in the metastasis of other tumors such as melanomas and breast cancers. Dr. Aifantis’s team also discovered that the gene for CCR7 was overactive in four of five T-ALL cell lines derived from human patients, bolstering suspicions that it played a central role in the disease. Conversely, a mutation that knocked out Notch1 also led to dramatically reduced CCR7 levels.
To characterize CCR7’s potential role in T-ALL, the researchers used two sets of mice: one in which the receptor was turned on, and a second in which it was turned off. When the team delivered an identical number of human-derived leukemic cells to both sets of mice, those with the CCR7 chemokine receptor turned off lived almost twice as long. Using bioluminescent imaging, the researchers quickly understood why: animals with the active CCR7 receptor had many more tumors. Tellingly, the T-ALL cells had infiltrated the brain and spinal cord of those mice.
Further experiments suggested that when healthy mice received leukemic cells in which the gene for CCR7 had been turned off, the cells could not migrate to the brain even though they reached other body tissues. As a result, the mice survived significantly longer than counterparts with an active copy of the gene. On the other hand, introducing a normal version of the same gene to mice otherwise lacking it was enough to recruit leukemic cells to the brain and spine.
“We wanted to determine whether CCR7 by itself was sufficient for entry into the central nervous system and that’s what this experiment shows,” Dr. Aifantis said. “By changing one specific gene, you now have your function back.”
Finally, the researchers identified the small protein that acted as the “come hither” signal for the CCR7 protein receptors. One candidate, CCL21, was undetectable in leukemic mice. But a second, CCL19, appeared in tiny veins of the brain near the infiltrating tumor cells. When the researchers introduced leukemic cells carrying a gene for CCR7 to mice that naturally lacked the CCL19 chemokine, the mice survived longer, suggesting that their increased life spans might be due to a disrupted interaction of the two proteins. The leukemic cells had no trouble infiltrating other tissue like the lymph nodes, but were completely incapable of infiltrating the brains of CCL19-deficient mice, the researchers report.
“Perhaps there are antibodies or small molecules that can block the interaction between these two proteins or reduce their interactions,” Dr. Aifantis said, “and hopefully that could be used as a type of prophylactic treatment to prevent a relapse in the central nervous system among patients who have already been treated for leukemia.” Such a treatment, he said, could prove a good alternative to the intensive and often poorly tolerated radiation and chemotherapy now used to try to block such a relapse.
The study was led by Dr. Silvia Buonamici, a post-doctoral fellow in the laboratory of Dr. Aifantis in the Department of Pathology and the NYU Cancer Institute, and in the Helen L. and Martin S. Kimmel Stem Cell Center at NYU Langone Medical Center. Other study investigators are; Thomas Trimarchi, Maria Grazia Ruocco, Linsey Reavie, Severine Cathelin, Yevgeniy Lukyanov, Jen-Chieh Tseng, Filiz Sen, Mengling Li, Elizabeth Newcomb, Jiri Zavadil, Daniel Meruelo, Sherif Ibrahim, David Zagzag, and Michael L. Dustin from NYU Langone Medical Center; Brenton G. Mar, Apostolos Klinakis, and Argiris Efstratiadis from Columbia University Medical Center; Eric Gehrie and Jonathan S. Bromberg from Mount Sinai School of Medicine; and Martin Lipp from the Max Delbrück Center for Molecular Medicine in Berlin.
The study was supported by grants from the National Institutes of Health, the American Cancer Society, the Dana Foundation, The Chemotherapy Foundation, the Alex’s Lemonade Stand Foundation, the Lauri Strauss Leukemia foundation, the G&P Foundation, an NYU School of Medicine Molecular Oncology and Immunology training grant, the American Society of Hematology, the Juvenile Diabetes Research Foundation, the National Cancer Institute, a gift from the Berrie Foundation, and a fellowship from the Jane Coffin Childs Memorial Fund for Medical Research.
About NYU Langone Medical Center
Located in New York City, NYU Langone Medical Center is one of the nation's premier centers of excellence in health care, biomedical research, and medical education. For over 168 years, NYU physicians and researchers have made countless contributions to the practice and science of health care. Today the Medical Center consists of NYU School of Medicine, including the Smilow Research Center, the Skirball Institute of Biomolecular Medicine, and the Sackler Institute of Graduate Biomedical Sciences; the three hospitals of NYU Hospitals Center, Tisch Hospital, a 705-bed acute-care general hospital, Rusk Institute of Rehabilitation Medicine, the first and largest facility of its kind, and NYU Hospital for Joint Diseases, a leader in musculoskeletal care; and such major programs as the NYU Cancer Institute, the NYU Child Study Center, and the Hassenfeld Children's Center for Cancer and Blood Disorders.
About NYU Cancer Institute
The NYU Cancer Institute is an NCI-designated cancer center. Its mission is to discover the origins of human cancer and to use that knowledge to eradicate the personal and societal burden of cancer in our community, the nation and the world. The center and its multidisciplinary team of experts provide access to the latest treatment options and clinical trials along with a variety of programs in cancer prevention, screening, diagnostics, genetic counseling and supportive services. For additional information, please visit: www.nyuci.org.
Despite great strides in treating childhood leukemia, a form of the disease called T-cell acute lymphoblastic leukemia (T-ALL) poses special challenges because of the high risk of leukemic cells invading the brain and spinal cord of children who relapse. Now, a new study in the June 18, 2009, issue of the journal Nature by scientists at NYU School of Medicine reveals the molecular agents behind this devastating infiltration of the central nervous system. The finding may lead to new drugs that block these agents and thus lower the risk of relapse. T-ALL, a blood-borne cancer in which the bone marrow makes too many lymphocytes, or white blood cells, strikes several hundred children and adolescents in the U.S. annually. While greater than 90% percent go into remission through a combination of chemotherapy and radiation, up to one third of this group end up relapsing. These patients are at particular risk for tumor cells to invade the brain and spinal cord, and to prevent this all patients receive chemotherapy injections into the central nervous system and in some cases cranial irradiation—approaches that cause dangerous side effects, including secondary tumors and potentially permanent cognitive and developmental deficits.
“In general, T-cell acute lymphoblastic leukemia is treatable with chemotherapy and radiation,” said Ioannis Aifantis, PhD, associate professor of pathology and co-director of the Cancer Stem Cell Program at the NYU Cancer Institute, who led the new study. “But you have a very high rate of relapse. And after the relapse, it is not treatable because the cancer occurs in tricky places like the central nervous system,” said Dr. Aifantis, who is also an Early Career Scientist at the Howard Hughes Medical Institute.
“We are very proud of this research and very excited about the potential implications for new therapeutic approaches to prevent or reduce the spread of leukemic cells into the central nervous system,” said Vivian S. Lee MD, PhD, MBA, the vice dean for science, senior vice president and chief scientific officer of NYU Langone Medical Center.
In the new study, Dr. Aifantis and his colleagues found that a key protein receptor embedded on the outer surface of leukemic cells is responsible for infiltrating the brain and spinal cord. “What we have found is that leukemic cells over-express this receptor.” said Dr. Aifantis, “If you knock out this receptor, these cells will not go to the brain under any circumstances.”
Previous research had strongly implicated a famous gene regulator called Notch1 in the progression of T-ALL. The Notch1 gene (a mutated version gives fruit flies notched wings) is an oncogene, or cancer-causing gene, in humans. Certain kinds of mutations in this gene have been found in nearly half of all T-ALL patients, and current estimates suggest that the gene’s regulatory influence might be implicated in nearly 90 percent of all T-ALL cases.
For their new study, Dr. Aifantis and his colleagues first introduced overactive forms of Notch1 into mice. As a result, the mice developed leukemia and the leukemic cells efficiently infiltrated the inner layers of the membrane covering the brain. “What happens is that the leukemic cells get into the cerebrospinal fluidthat protects our brain and spine, where they fill up the space and they can affect brain function, either by secreting chemicals and toxic factors or even by simple pressure,” Dr. Aifantis said.
His team then examined an array of other mouse genes to identify candidates that might fall under the regulatory spell of Notch1 to promote the brain and spinal cord infiltration. The screen revealed a promising gene for a protein named CCR7, which is embedded on the surface of lymphocytes. This chemokine receptor, as it’s known, normally senses and responds to small chemical attractants called chemokines, which act like recruitment signals for lymphocytes to converge on a specific site during the body’s response to infection or injury. In leukemia, however, these lymphocytes proliferate abnormally.
CCR7 was already known as a key player in normal lymphocyte migration and as a binding partner of two chemokines named CCL19 and CCL21. Previous studies had implicated these protein interactions in the metastasis of other tumors such as melanomas and breast cancers. Dr. Aifantis’s team also discovered that the gene for CCR7 was overactive in four of five T-ALL cell lines derived from human patients, bolstering suspicions that it played a central role in the disease. Conversely, a mutation that knocked out Notch1 also led to dramatically reduced CCR7 levels.
To characterize CCR7’s potential role in T-ALL, the researchers used two sets of mice: one in which the receptor was turned on, and a second in which it was turned off. When the team delivered an identical number of human-derived leukemic cells to both sets of mice, those with the CCR7 chemokine receptor turned off lived almost twice as long. Using bioluminescent imaging, the researchers quickly understood why: animals with the active CCR7 receptor had many more tumors. Tellingly, the T-ALL cells had infiltrated the brain and spinal cord of those mice.
Further experiments suggested that when healthy mice received leukemic cells in which the gene for CCR7 had been turned off, the cells could not migrate to the brain even though they reached other body tissues. As a result, the mice survived significantly longer than counterparts with an active copy of the gene. On the other hand, introducing a normal version of the same gene to mice otherwise lacking it was enough to recruit leukemic cells to the brain and spine.
“We wanted to determine whether CCR7 by itself was sufficient for entry into the central nervous system and that’s what this experiment shows,” Dr. Aifantis said. “By changing one specific gene, you now have your function back.”
Finally, the researchers identified the small protein that acted as the “come hither” signal for the CCR7 protein receptors. One candidate, CCL21, was undetectable in leukemic mice. But a second, CCL19, appeared in tiny veins of the brain near the infiltrating tumor cells. When the researchers introduced leukemic cells carrying a gene for CCR7 to mice that naturally lacked the CCL19 chemokine, the mice survived longer, suggesting that their increased life spans might be due to a disrupted interaction of the two proteins. The leukemic cells had no trouble infiltrating other tissue like the lymph nodes, but were completely incapable of infiltrating the brains of CCL19-deficient mice, the researchers report.
“Perhaps there are antibodies or small molecules that can block the interaction between these two proteins or reduce their interactions,” Dr. Aifantis said, “and hopefully that could be used as a type of prophylactic treatment to prevent a relapse in the central nervous system among patients who have already been treated for leukemia.” Such a treatment, he said, could prove a good alternative to the intensive and often poorly tolerated radiation and chemotherapy now used to try to block such a relapse.
The study was led by Dr. Silvia Buonamici, a post-doctoral fellow in the laboratory of Dr. Aifantis in the Department of Pathology and the NYU Cancer Institute, and in the Helen L. and Martin S. Kimmel Stem Cell Center at NYU Langone Medical Center. Other study investigators are; Thomas Trimarchi, Maria Grazia Ruocco, Linsey Reavie, Severine Cathelin, Yevgeniy Lukyanov, Jen-Chieh Tseng, Filiz Sen, Mengling Li, Elizabeth Newcomb, Jiri Zavadil, Daniel Meruelo, Sherif Ibrahim, David Zagzag, and Michael L. Dustin from NYU Langone Medical Center; Brenton G. Mar, Apostolos Klinakis, and Argiris Efstratiadis from Columbia University Medical Center; Eric Gehrie and Jonathan S. Bromberg from Mount Sinai School of Medicine; and Martin Lipp from the Max Delbrück Center for Molecular Medicine in Berlin.
The study was supported by grants from the National Institutes of Health, the American Cancer Society, the Dana Foundation, The Chemotherapy Foundation, the Alex’s Lemonade Stand Foundation, the Lauri Strauss Leukemia foundation, the G&P Foundation, an NYU School of Medicine Molecular Oncology and Immunology training grant, the American Society of Hematology, the Juvenile Diabetes Research Foundation, the National Cancer Institute, a gift from the Berrie Foundation, and a fellowship from the Jane Coffin Childs Memorial Fund for Medical Research.
About NYU Langone Medical Center
Located in New York City, NYU Langone Medical Center is one of the nation's premier centers of excellence in health care, biomedical research, and medical education. For over 168 years, NYU physicians and researchers have made countless contributions to the practice and science of health care. Today the Medical Center consists of NYU School of Medicine, including the Smilow Research Center, the Skirball Institute of Biomolecular Medicine, and the Sackler Institute of Graduate Biomedical Sciences; the three hospitals of NYU Hospitals Center, Tisch Hospital, a 705-bed acute-care general hospital, Rusk Institute of Rehabilitation Medicine, the first and largest facility of its kind, and NYU Hospital for Joint Diseases, a leader in musculoskeletal care; and such major programs as the NYU Cancer Institute, the NYU Child Study Center, and the Hassenfeld Children's Center for Cancer and Blood Disorders.
About NYU Cancer Institute
The NYU Cancer Institute is an NCI-designated cancer center. Its mission is to discover the origins of human cancer and to use that knowledge to eradicate the personal and societal burden of cancer in our community, the nation and the world. The center and its multidisciplinary team of experts provide access to the latest treatment options and clinical trials along with a variety of programs in cancer prevention, screening, diagnostics, genetic counseling and supportive services. For additional information, please visit: www.nyuci.org.
Tuesday, June 09, 2009
Confusion About Sugars
Three top researchers corrected inaccuracies and misunderstandings concerning high fructose corn syrup's impact on the American diet. They also examined how the United States Department of Agriculture (USDA) considers this sweetener in light of the upcoming 2010 Dietary Guidelines for Americans in a session, High Fructose Corn Syrup: Sorting Myth from Reality, at the Institute of Food Technologists (IFT) Annual Meeting in Anaheim, California.
"Contrary to its name, high fructose corn syrup is essentially a corn sugar," stated sweetener expert John S. White, Ph.D., president of White Technical Research. "Recent marketing claims that sugar is healthier than high fructose corn syrup are misleading to consumers."
"By every parameter yet measured in human beings, high fructose corn syrup and sugar are identical. This is not surprising since high fructose corn syrup and sugar are metabolized the same by the body, have the same level of sweetness and the same number of calories per gram," noted James M. Rippe, M.D., cardiologist and biomedical sciences professor at the University of Central Florida.
"This is a marketing issue, not a metabolic issue," stated David Klurfeld, Ph.D., national program leader for human nutrition in USDA's Agricultural Research Service and editor of the June 2009 Journal of Nutrition supplement, "The State of the Science on Dietary Sweeteners Containing Fructose," in response to recent reformulations by manufacturers of products that once contained high fructose corn syrup. "The real issue is not high fructose corn syrup. It's that we've forgotten what a real serving size is. We have to eat less of everything," he noted.
Increased Caloric Intake, Not a Single Sweetener, the Likely Cause of Obesity
Fructose-containing sweeteners -- such as sugar, invert sugar, honey, fruit juice concentrates, and high fructose corn syrup -- are essentially interchangeable in composition, calories, and metabolism. Replacing high fructose corn syrup in foods with other fructose-containing sweeteners will provide neither improved nutrition nor a meaningful solution to the obesity crisis, according to Dr. White. "In light of similarities in composition, sweetness, energy content, processing, and metabolism, claims that such sweetener substitutions bring nutritional benefit to children and their families appear disingenuous and misguided," White says.
Growing Body of Evidence
The American Medical Association helped put to rest a common misunderstanding about high fructose corn syrup and obesity, stating that "high fructose syrup does not appear to contribute to obesity more than other caloric sweeteners." Even former critics of high fructose corn syrup dispelled myths and distanced themselves from earlier speculation about the sweetener's link to obesity in a comprehensive scientific review published in the December 2008 American Journal of Clinical Nutrition.
Three top researchers corrected inaccuracies and misunderstandings concerning high fructose corn syrup's impact on the American diet. They also examined how the United States Department of Agriculture (USDA) considers this sweetener in light of the upcoming 2010 Dietary Guidelines for Americans in a session, High Fructose Corn Syrup: Sorting Myth from Reality, at the Institute of Food Technologists (IFT) Annual Meeting in Anaheim, California.
"Contrary to its name, high fructose corn syrup is essentially a corn sugar," stated sweetener expert John S. White, Ph.D., president of White Technical Research. "Recent marketing claims that sugar is healthier than high fructose corn syrup are misleading to consumers."
"By every parameter yet measured in human beings, high fructose corn syrup and sugar are identical. This is not surprising since high fructose corn syrup and sugar are metabolized the same by the body, have the same level of sweetness and the same number of calories per gram," noted James M. Rippe, M.D., cardiologist and biomedical sciences professor at the University of Central Florida.
"This is a marketing issue, not a metabolic issue," stated David Klurfeld, Ph.D., national program leader for human nutrition in USDA's Agricultural Research Service and editor of the June 2009 Journal of Nutrition supplement, "The State of the Science on Dietary Sweeteners Containing Fructose," in response to recent reformulations by manufacturers of products that once contained high fructose corn syrup. "The real issue is not high fructose corn syrup. It's that we've forgotten what a real serving size is. We have to eat less of everything," he noted.
Increased Caloric Intake, Not a Single Sweetener, the Likely Cause of Obesity
Fructose-containing sweeteners -- such as sugar, invert sugar, honey, fruit juice concentrates, and high fructose corn syrup -- are essentially interchangeable in composition, calories, and metabolism. Replacing high fructose corn syrup in foods with other fructose-containing sweeteners will provide neither improved nutrition nor a meaningful solution to the obesity crisis, according to Dr. White. "In light of similarities in composition, sweetness, energy content, processing, and metabolism, claims that such sweetener substitutions bring nutritional benefit to children and their families appear disingenuous and misguided," White says.
Growing Body of Evidence
The American Medical Association helped put to rest a common misunderstanding about high fructose corn syrup and obesity, stating that "high fructose syrup does not appear to contribute to obesity more than other caloric sweeteners." Even former critics of high fructose corn syrup dispelled myths and distanced themselves from earlier speculation about the sweetener's link to obesity in a comprehensive scientific review published in the December 2008 American Journal of Clinical Nutrition.
Saturday, May 02, 2009
Researchers Construct Carbon Nanotube Device That Can Detect Colors of the Rainbow
Researchers at Sandia National Laboratories have created the first carbon nanotube device that can detect the entire visible spectrum of light, a feat that could soon allow scientists to probe single molecule transformations, study how those molecules respond to light, observe how the molecules change shapes, and understand other fundamental interactions between molecules and nanotubes.
Carbon nanotubes are long thin cylinders composed entirely of carbon atoms. While their diameters are in the nanometer range (1-10), they can be very long, up to centimeters in length.
The carbon-carbon bond is very strong, making carbon nanotubes very robust and resistant to any kind of deformation. To construct a nanoscale color detector, Sandia researchers took inspiration from the human eye, and in a sense, improved on the model.
When light strikes the retina, it initiates a cascade of chemical and electrical impulses that ultimately trigger nerve impulses. In the nanoscale color detector, light strikes a chromophore and causes a conformational change in the molecule, which in turn causes a threshold shift on a transistor made from a single-walled carbon nanotube.
“In our eyes the neuron is in front of the retinal molecule, so the light has to transmit through the neuron to hit the molecule,” says Sandia researcher Xinjian Zhou. “We placed the nanotube transistor behind the molecule—a more efficient design.”
Zhou and his Sandia colleagues François Léonard, Andy Vance, Karen Krafcik, Tom Zifer, and Bryan Wong created the device. The team recently published a paper, “Color Detection Using Chromophore-Nanotube Hybrid Devices,” in the journal Nano Letters.
The idea of carbon nanotubes being light sensitive has been around for a long time, but earlier efforts using an individual nanotube were only able to detect light in narrow wavelength ranges at laser intensities. The Sandia team found that their nanodetector was orders of magnitude more sensitive, down to about 40 W/m2—about 3 percent of the density of sunshine reaching the ground. “Because the dye is so close to the nanotube, a little change turns into a big signal on the device,” says Zhou.
The research is in its second year of internal Sandia funding and is based on Léonard’s collaboration with the University of Wisconsin to explain the theoretical mechanism of carbon nanotube light detection. Léonard literally wrote the book on carbon nanotubes—The Physics of Carbon Nanotubes, published September 2008.
Léonard says the project draws upon Sandia’s expertise in both materials physics and materials chemistry. He and Wong laid the groundwork with their theoretical research, with Wong completing the first-principles calculations that supported the hypothesis of how the chromophores were arranged on the nanotubes and how the chromophore isomerizations affected electronic properties of the devices.
To construct the device, Zhou and Krafcik first had to create a tiny transistor made from a single carbon nanotube. They deposited carbon nanotubes on a silicon wafer and then used photolithography to define electrical patterns to make contacts.
The final piece came from Vance and Zifer, who synthesized molecules to create three types of chromophores that respond to either the red, green, or orange bands of the visible spectrum. Zhou immersed the wafer in the dye solution and waited a few minutes while the chromophores attached themselves to the nanotubes.
The team reached their goal of detecting visible light faster than they expected—they thought the entire first year of the project would be spent testing UV light. Now, they are looking to increase the efficiency by creating a device with multiple nanotubes.
“Detection is now limited to about 3 percent of sunlight, which isn’t bad compared with a commercially available digital camera,” says Zhou. “I hope to add some antennas to increase light absorption.”
A device made with multiple carbon nanotubes would be easier to construct and the resulting larger area would be more sensitive to light. A larger size is also more practical for applications.
Now, they are setting their sites on detecting infrared light. “We think this principle can be applied to infrared light and there is a lot of interest in infrared detection,” says Vance. “So we’re in the process of looking for dyes that work in infrared.”
This research eventually could be used for a number of exciting applications, such as an optical detector with nanometer scale resolution, ultra-tiny digital cameras, solar cells with more light absorption capability, or even genome sequencing. The near-term purpose, however, is basic science.
“A large part of why we are doing this is not to invent a photo detector, but to understand the processes involved in controlling carbon nanotube devices,” says Léonard.
The next step in the project is to create a nanometer-scale photovoltaic device. Such a device on a larger scale could be used as an unpowered photo detector or for solar energy. “Instead of monitoring current changes, we’d actually generate current,” says Vance. “We have an idea of how to do it, but it will be a more challenging fabrication process.”
--------------------------------------------------------------------------------
Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin company, for the U.S. Department of Energy’s National Nuclear Security Administration. With main facilities in Albuquerque, N.M., and Livermore, Calif.Researchers at Sandia National Laboratories have created the first carbon nanotube device that can detect the entire visible spectrum of light, a feat that could soon allow scientists to probe single molecule transformations, study how those molecules respond to light, observe how the molecules change shapes, and understand other fundamental interactions between molecules and nanotubes.
Carbon nanotubes are long thin cylinders composed entirely of carbon atoms. While their diameters are in the nanometer range (1-10), they can be very long, up to centimeters in length.
The carbon-carbon bond is very strong, making carbon nanotubes very robust and resistant to any kind of deformation. To construct a nanoscale color detector, Sandia researchers took inspiration from the human eye, and in a sense, improved on the model.
When light strikes the retina, it initiates a cascade of chemical and electrical impulses that ultimately trigger nerve impulses. In the nanoscale color detector, light strikes a chromophore and causes a conformational change in the molecule, which in turn causes a threshold shift on a transistor made from a single-walled carbon nanotube.
“In our eyes the neuron is in front of the retinal molecule, so the light has to transmit through the neuron to hit the molecule,” says Sandia researcher Xinjian Zhou. “We placed the nanotube transistor behind the molecule—a more efficient design.”
Zhou and his Sandia colleagues François Léonard, Andy Vance, Karen Krafcik, Tom Zifer, and Bryan Wong created the device. The team recently published a paper, “Color Detection Using Chromophore-Nanotube Hybrid Devices,” in the journal Nano Letters.
The idea of carbon nanotubes being light sensitive has been around for a long time, but earlier efforts using an individual nanotube were only able to detect light in narrow wavelength ranges at laser intensities. The Sandia team found that their nanodetector was orders of magnitude more sensitive, down to about 40 W/m2—about 3 percent of the density of sunshine reaching the ground. “Because the dye is so close to the nanotube, a little change turns into a big signal on the device,” says Zhou.
The research is in its second year of internal Sandia funding and is based on Léonard’s collaboration with the University of Wisconsin to explain the theoretical mechanism of carbon nanotube light detection. Léonard literally wrote the book on carbon nanotubes—The Physics of Carbon Nanotubes, published September 2008.
Léonard says the project draws upon Sandia’s expertise in both materials physics and materials chemistry. He and Wong laid the groundwork with their theoretical research, with Wong completing the first-principles calculations that supported the hypothesis of how the chromophores were arranged on the nanotubes and how the chromophore isomerizations affected electronic properties of the devices.
To construct the device, Zhou and Krafcik first had to create a tiny transistor made from a single carbon nanotube. They deposited carbon nanotubes on a silicon wafer and then used photolithography to define electrical patterns to make contacts.
The final piece came from Vance and Zifer, who synthesized molecules to create three types of chromophores that respond to either the red, green, or orange bands of the visible spectrum. Zhou immersed the wafer in the dye solution and waited a few minutes while the chromophores attached themselves to the nanotubes.
The team reached their goal of detecting visible light faster than they expected—they thought the entire first year of the project would be spent testing UV light. Now, they are looking to increase the efficiency by creating a device with multiple nanotubes.
“Detection is now limited to about 3 percent of sunlight, which isn’t bad compared with a commercially available digital camera,” says Zhou. “I hope to add some antennas to increase light absorption.”
A device made with multiple carbon nanotubes would be easier to construct and the resulting larger area would be more sensitive to light. A larger size is also more practical for applications.
Now, they are setting their sites on detecting infrared light. “We think this principle can be applied to infrared light and there is a lot of interest in infrared detection,” says Vance. “So we’re in the process of looking for dyes that work in infrared.”
This research eventually could be used for a number of exciting applications, such as an optical detector with nanometer scale resolution, ultra-tiny digital cameras, solar cells with more light absorption capability, or even genome sequencing. The near-term purpose, however, is basic science.
“A large part of why we are doing this is not to invent a photo detector, but to understand the processes involved in controlling carbon nanotube devices,” says Léonard.
The next step in the project is to create a nanometer-scale photovoltaic device. Such a device on a larger scale could be used as an unpowered photo detector or for solar energy. “Instead of monitoring current changes, we’d actually generate current,” says Vance. “We have an idea of how to do it, but it will be a more challenging fabrication process.”
--------------------------------------------------------------------------------
Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin company, for the U.S. Department of Energy’s National Nuclear Security Administration. With main facilities in Albuquerque, N.M., and Livermore, Calif.
Sandia has major R&D responsibilities in national security, energy and environmental technologies, and economic competitiveness.
Researchers at Sandia National Laboratories have created the first carbon nanotube device that can detect the entire visible spectrum of light, a feat that could soon allow scientists to probe single molecule transformations, study how those molecules respond to light, observe how the molecules change shapes, and understand other fundamental interactions between molecules and nanotubes.
Carbon nanotubes are long thin cylinders composed entirely of carbon atoms. While their diameters are in the nanometer range (1-10), they can be very long, up to centimeters in length.
The carbon-carbon bond is very strong, making carbon nanotubes very robust and resistant to any kind of deformation. To construct a nanoscale color detector, Sandia researchers took inspiration from the human eye, and in a sense, improved on the model.
When light strikes the retina, it initiates a cascade of chemical and electrical impulses that ultimately trigger nerve impulses. In the nanoscale color detector, light strikes a chromophore and causes a conformational change in the molecule, which in turn causes a threshold shift on a transistor made from a single-walled carbon nanotube.
“In our eyes the neuron is in front of the retinal molecule, so the light has to transmit through the neuron to hit the molecule,” says Sandia researcher Xinjian Zhou. “We placed the nanotube transistor behind the molecule—a more efficient design.”
Zhou and his Sandia colleagues François Léonard, Andy Vance, Karen Krafcik, Tom Zifer, and Bryan Wong created the device. The team recently published a paper, “Color Detection Using Chromophore-Nanotube Hybrid Devices,” in the journal Nano Letters.
The idea of carbon nanotubes being light sensitive has been around for a long time, but earlier efforts using an individual nanotube were only able to detect light in narrow wavelength ranges at laser intensities. The Sandia team found that their nanodetector was orders of magnitude more sensitive, down to about 40 W/m2—about 3 percent of the density of sunshine reaching the ground. “Because the dye is so close to the nanotube, a little change turns into a big signal on the device,” says Zhou.
The research is in its second year of internal Sandia funding and is based on Léonard’s collaboration with the University of Wisconsin to explain the theoretical mechanism of carbon nanotube light detection. Léonard literally wrote the book on carbon nanotubes—The Physics of Carbon Nanotubes, published September 2008.
Léonard says the project draws upon Sandia’s expertise in both materials physics and materials chemistry. He and Wong laid the groundwork with their theoretical research, with Wong completing the first-principles calculations that supported the hypothesis of how the chromophores were arranged on the nanotubes and how the chromophore isomerizations affected electronic properties of the devices.
To construct the device, Zhou and Krafcik first had to create a tiny transistor made from a single carbon nanotube. They deposited carbon nanotubes on a silicon wafer and then used photolithography to define electrical patterns to make contacts.
The final piece came from Vance and Zifer, who synthesized molecules to create three types of chromophores that respond to either the red, green, or orange bands of the visible spectrum. Zhou immersed the wafer in the dye solution and waited a few minutes while the chromophores attached themselves to the nanotubes.
The team reached their goal of detecting visible light faster than they expected—they thought the entire first year of the project would be spent testing UV light. Now, they are looking to increase the efficiency by creating a device with multiple nanotubes.
“Detection is now limited to about 3 percent of sunlight, which isn’t bad compared with a commercially available digital camera,” says Zhou. “I hope to add some antennas to increase light absorption.”
A device made with multiple carbon nanotubes would be easier to construct and the resulting larger area would be more sensitive to light. A larger size is also more practical for applications.
Now, they are setting their sites on detecting infrared light. “We think this principle can be applied to infrared light and there is a lot of interest in infrared detection,” says Vance. “So we’re in the process of looking for dyes that work in infrared.”
This research eventually could be used for a number of exciting applications, such as an optical detector with nanometer scale resolution, ultra-tiny digital cameras, solar cells with more light absorption capability, or even genome sequencing. The near-term purpose, however, is basic science.
“A large part of why we are doing this is not to invent a photo detector, but to understand the processes involved in controlling carbon nanotube devices,” says Léonard.
The next step in the project is to create a nanometer-scale photovoltaic device. Such a device on a larger scale could be used as an unpowered photo detector or for solar energy. “Instead of monitoring current changes, we’d actually generate current,” says Vance. “We have an idea of how to do it, but it will be a more challenging fabrication process.”
--------------------------------------------------------------------------------
Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin company, for the U.S. Department of Energy’s National Nuclear Security Administration. With main facilities in Albuquerque, N.M., and Livermore, Calif.Researchers at Sandia National Laboratories have created the first carbon nanotube device that can detect the entire visible spectrum of light, a feat that could soon allow scientists to probe single molecule transformations, study how those molecules respond to light, observe how the molecules change shapes, and understand other fundamental interactions between molecules and nanotubes.
Carbon nanotubes are long thin cylinders composed entirely of carbon atoms. While their diameters are in the nanometer range (1-10), they can be very long, up to centimeters in length.
The carbon-carbon bond is very strong, making carbon nanotubes very robust and resistant to any kind of deformation. To construct a nanoscale color detector, Sandia researchers took inspiration from the human eye, and in a sense, improved on the model.
When light strikes the retina, it initiates a cascade of chemical and electrical impulses that ultimately trigger nerve impulses. In the nanoscale color detector, light strikes a chromophore and causes a conformational change in the molecule, which in turn causes a threshold shift on a transistor made from a single-walled carbon nanotube.
“In our eyes the neuron is in front of the retinal molecule, so the light has to transmit through the neuron to hit the molecule,” says Sandia researcher Xinjian Zhou. “We placed the nanotube transistor behind the molecule—a more efficient design.”
Zhou and his Sandia colleagues François Léonard, Andy Vance, Karen Krafcik, Tom Zifer, and Bryan Wong created the device. The team recently published a paper, “Color Detection Using Chromophore-Nanotube Hybrid Devices,” in the journal Nano Letters.
The idea of carbon nanotubes being light sensitive has been around for a long time, but earlier efforts using an individual nanotube were only able to detect light in narrow wavelength ranges at laser intensities. The Sandia team found that their nanodetector was orders of magnitude more sensitive, down to about 40 W/m2—about 3 percent of the density of sunshine reaching the ground. “Because the dye is so close to the nanotube, a little change turns into a big signal on the device,” says Zhou.
The research is in its second year of internal Sandia funding and is based on Léonard’s collaboration with the University of Wisconsin to explain the theoretical mechanism of carbon nanotube light detection. Léonard literally wrote the book on carbon nanotubes—The Physics of Carbon Nanotubes, published September 2008.
Léonard says the project draws upon Sandia’s expertise in both materials physics and materials chemistry. He and Wong laid the groundwork with their theoretical research, with Wong completing the first-principles calculations that supported the hypothesis of how the chromophores were arranged on the nanotubes and how the chromophore isomerizations affected electronic properties of the devices.
To construct the device, Zhou and Krafcik first had to create a tiny transistor made from a single carbon nanotube. They deposited carbon nanotubes on a silicon wafer and then used photolithography to define electrical patterns to make contacts.
The final piece came from Vance and Zifer, who synthesized molecules to create three types of chromophores that respond to either the red, green, or orange bands of the visible spectrum. Zhou immersed the wafer in the dye solution and waited a few minutes while the chromophores attached themselves to the nanotubes.
The team reached their goal of detecting visible light faster than they expected—they thought the entire first year of the project would be spent testing UV light. Now, they are looking to increase the efficiency by creating a device with multiple nanotubes.
“Detection is now limited to about 3 percent of sunlight, which isn’t bad compared with a commercially available digital camera,” says Zhou. “I hope to add some antennas to increase light absorption.”
A device made with multiple carbon nanotubes would be easier to construct and the resulting larger area would be more sensitive to light. A larger size is also more practical for applications.
Now, they are setting their sites on detecting infrared light. “We think this principle can be applied to infrared light and there is a lot of interest in infrared detection,” says Vance. “So we’re in the process of looking for dyes that work in infrared.”
This research eventually could be used for a number of exciting applications, such as an optical detector with nanometer scale resolution, ultra-tiny digital cameras, solar cells with more light absorption capability, or even genome sequencing. The near-term purpose, however, is basic science.
“A large part of why we are doing this is not to invent a photo detector, but to understand the processes involved in controlling carbon nanotube devices,” says Léonard.
The next step in the project is to create a nanometer-scale photovoltaic device. Such a device on a larger scale could be used as an unpowered photo detector or for solar energy. “Instead of monitoring current changes, we’d actually generate current,” says Vance. “We have an idea of how to do it, but it will be a more challenging fabrication process.”
--------------------------------------------------------------------------------
Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin company, for the U.S. Department of Energy’s National Nuclear Security Administration. With main facilities in Albuquerque, N.M., and Livermore, Calif.
Sandia has major R&D responsibilities in national security, energy and environmental technologies, and economic competitiveness.
Saturday, April 25, 2009
Vitamin D 'is a hormone'
A new study has suggested that vitamin D isn't really a vitamin at all -- it's actually a hormone made inside the body without any help from the sun.
An international team has carried out the study and concluded that the increase of vitamin D in our modern diets is based on a common belief which is actually a misconception with potential consequences.
ÒWhat we have confirmed with our recent research is that vitamin D is a hormone that is made by the body itself. Our bodies hormonal control system was being overwhelmed by the amount of external vitamin D,Ó lead researcher Prof Trevor G Marshall at Murdoch University in Australia said.
The researchers go on to explode another long held belief about this secosteriod previously known as vitamin D. ÒYou don't have to ingest any vitamin D in order to be perfectly healthy,Ó Prof Marshall said.
So no more need for expensive supplements, no more basking in the sun to put us in a better mood? And what about the thinking that suggests vitamin D is vital in production of serotonin, an essential element linked to helping maintaining normal brain chemical function? ÓWhat we've shown is that all forms of vitamin D from outside the body are counterproductive to body's own ability to regulate its own internal production,Ó he said.
This conclusion doesn't mean a dramatic change of lifestyle where we must all suddenly shun the sun but the researchers do acknowledge that people have only been at risk of vitamin D overexposure from about the same time as when bikinis made an appearance.
ÒHistorically the amount of sunshine which people have typically been getting was adequate, certainly up until the mid twentieth century when we started to do silly things like sunbathing and wearing bikinis, and before that time people were already sourcing enough vitamin D from everyday foods like fish, mushrooms and eggs,Ó Prof Marshall said.
A new study has suggested that vitamin D isn't really a vitamin at all -- it's actually a hormone made inside the body without any help from the sun.
An international team has carried out the study and concluded that the increase of vitamin D in our modern diets is based on a common belief which is actually a misconception with potential consequences.
ÒWhat we have confirmed with our recent research is that vitamin D is a hormone that is made by the body itself. Our bodies hormonal control system was being overwhelmed by the amount of external vitamin D,Ó lead researcher Prof Trevor G Marshall at Murdoch University in Australia said.
The researchers go on to explode another long held belief about this secosteriod previously known as vitamin D. ÒYou don't have to ingest any vitamin D in order to be perfectly healthy,Ó Prof Marshall said.
So no more need for expensive supplements, no more basking in the sun to put us in a better mood? And what about the thinking that suggests vitamin D is vital in production of serotonin, an essential element linked to helping maintaining normal brain chemical function? ÓWhat we've shown is that all forms of vitamin D from outside the body are counterproductive to body's own ability to regulate its own internal production,Ó he said.
This conclusion doesn't mean a dramatic change of lifestyle where we must all suddenly shun the sun but the researchers do acknowledge that people have only been at risk of vitamin D overexposure from about the same time as when bikinis made an appearance.
ÒHistorically the amount of sunshine which people have typically been getting was adequate, certainly up until the mid twentieth century when we started to do silly things like sunbathing and wearing bikinis, and before that time people were already sourcing enough vitamin D from everyday foods like fish, mushrooms and eggs,Ó Prof Marshall said.
The World’s First, High Performance & Environmentally Benign Power Generation Unit
If the device is applied to 30% of the cars in Japan, we can expect a 960,000kl oil substitution effect which is 1.5 times the assumed effect from solar energy generation of the year 2010.
A research team led by associate professor Tsutomu Iida (Tokyo University of Science - Faculty of Industrial Science and Technology – Materials Science and Technology) has developed a power generation unit driven by wasted heat composed of Magnesium silicide (Mg2Si), a filtered by-product of Si-LSI and solar cell cast wafer production.
This device, being the first in the world, has been successful in bulk-quantity synthesis, at the same time increasing the thermoelectric conversion rate. Approximately 2,500W/m² (per unit) of power generation and 3,000 hrs of continuous operation has been made possible, sufficiently fulfilling the criteria for commercial use.
By applying this device in industrial shaft furnaces and/or car engines, we can expect drastic reduction in fuel consumption and prevention of global warming. Implementation of this device has already been determined partially as an experiment for practical use and there are high expectations of application of this device in industrial furnaces nation-wide.
Mg2Si Power Generation Unit Driven by Waste Heat - Capability & Effect; This device has an effective temperature range from 200 degree to 600 degree; hence, there is high hope for implementation in industrial furnaces, cars, etc. When applied to gas-powered vehicles, 500~1,000W of electrical energy can be recycled, increasing the energy use efficiency.
If the device is applied to 30% of the cars in Japan, we can expect a 960,000kl oil substitution effect which is 1.5 times the assumed effect from solar energy generation of the year 2010. Also, if the device is implemented in industrial shaft furnaces which have an approximately 10% energy use efficiency, the efficiency will increase by 1.5 times and CO2 emission will be reduced by one-third. Iida’s research team is continuing research for further improvement in energy conversion and durability of the device.
Background of R&D and Success of Material Development;
Today, our main source of energy is fossil fuel. However the energy use efficiency has only gone up to 30% leaving 70% to be disposed as “wasted heat”. Efficiently reusing “wasted heat” and reducing fossil fuel consumption and CO2 emission, from the perspective of preventing global warming, has attracted attention from all around the world. The popularization of power generation from wasted heat has gone through many obstacles such as scarcity of material, cost, toxicity, etc. Iida’s research team has focused on the low cost and environmentally friendly silicon.
They have successfully managed to mass produce Magnesium silicide (Mg2Si), from the by-product of Si-LSI and solar cell cast wafer production, providing high-performance in power generation driven by wasted heat.
- Progress of Research -
Discovery of Magnesium silicide, material for Thermoelectric Conversion driven by Wasted Heat
Heretofore the compound of Lead and Tellurium (Pb-Te), have been known to be the material for thermoelectric conversion from wasted heat. However, Lead being hazardous and Tellurium being scarce, development of new material of low environmental burden was hoped for. Iida’s research team has been successful in being pioneers of mass producing Magnesium silicide from Silicon which is found abundantly on earth, holding the characteristic of being nonhazardous. Through this discovery of environmentally benign material, the realization of an environmentally benign technology of thermoelectric conversion through wasted heat was made possible.
Development of Magnesium silicide from Silicon by-product Silicon, being the main raw material for Magnesium silicide, is widely known to be a necessary ingredient for semiconductors throughout the electronic industry. However, in production of ultrapure silicon, much energy is consumed and more than half of the material comes out as Silicon sludge, usually being disposed of. This not only pollutes the environment, but raises the cost of production and also prevents further development of new materials and/or technology.
The research team has been successful in mass producing material for thermoelectric conversion through this waste product at a substantially low cost. Through this, thermoelectric conversion from wasted heat has become even more environmentally benign.
Profile - Tsutomu Iida
Background:
March, 1995: Meiji University Graduate School – completed PhD course
April, 1995: Japan Society for the Promotion of Science – Fellowship
July, 1995: Federal Republic of Germany – Volkswagen Foundation
April, 1997: Tokyo University of Science - Faculty of Industrial
Science and Technology – Materials Science and Technology
To Present
Major Field: Semiconductor Material Engineering
Field of Research: Semiconductor Energy Material (Thermoelectric Material / Solar Cell Material) ‘Environmentally Friendly’ Semiconductor Material
Research Content: Due to mass consumption of fossil fuel and also
for prevention of global warming, research and development of energy conversion materials are being conducted. Solar energy being the main source of reusable energy, development of solar cell material and thermoelectric conversion material is being conducted. Due to the fact that many elemental devices which are used for energy conversion tending to be toxic, development of environmentally benign semiconductor energy material continues to be conducted. Environmentally benign semiconductors are composed of semiconductor material which abundantly exists on earth and is highly ‘earth-friendly’.
Research Content:
1. Development of Thermoelectric Conversion Elemental Device through Magnesium silicide
2. Development of High Efficiency Solar Cells through Silicon Germanium
3. Photodecomposition and Hydrogen Composition of water through Semiconductor Photocatalyst
Website:http://web.mac.com/iida_lab/
Contact for this information -
Tokyo University of Science Technology Licensing Organization
Administrator: Niki
TEL: 03-5225-1089
e-mail:niki_tamotsu@admin.tus.ac.jp
If the device is applied to 30% of the cars in Japan, we can expect a 960,000kl oil substitution effect which is 1.5 times the assumed effect from solar energy generation of the year 2010.
A research team led by associate professor Tsutomu Iida (Tokyo University of Science - Faculty of Industrial Science and Technology – Materials Science and Technology) has developed a power generation unit driven by wasted heat composed of Magnesium silicide (Mg2Si), a filtered by-product of Si-LSI and solar cell cast wafer production.
This device, being the first in the world, has been successful in bulk-quantity synthesis, at the same time increasing the thermoelectric conversion rate. Approximately 2,500W/m² (per unit) of power generation and 3,000 hrs of continuous operation has been made possible, sufficiently fulfilling the criteria for commercial use.
By applying this device in industrial shaft furnaces and/or car engines, we can expect drastic reduction in fuel consumption and prevention of global warming. Implementation of this device has already been determined partially as an experiment for practical use and there are high expectations of application of this device in industrial furnaces nation-wide.
Mg2Si Power Generation Unit Driven by Waste Heat - Capability & Effect; This device has an effective temperature range from 200 degree to 600 degree; hence, there is high hope for implementation in industrial furnaces, cars, etc. When applied to gas-powered vehicles, 500~1,000W of electrical energy can be recycled, increasing the energy use efficiency.
If the device is applied to 30% of the cars in Japan, we can expect a 960,000kl oil substitution effect which is 1.5 times the assumed effect from solar energy generation of the year 2010. Also, if the device is implemented in industrial shaft furnaces which have an approximately 10% energy use efficiency, the efficiency will increase by 1.5 times and CO2 emission will be reduced by one-third. Iida’s research team is continuing research for further improvement in energy conversion and durability of the device.
Background of R&D and Success of Material Development;
Today, our main source of energy is fossil fuel. However the energy use efficiency has only gone up to 30% leaving 70% to be disposed as “wasted heat”. Efficiently reusing “wasted heat” and reducing fossil fuel consumption and CO2 emission, from the perspective of preventing global warming, has attracted attention from all around the world. The popularization of power generation from wasted heat has gone through many obstacles such as scarcity of material, cost, toxicity, etc. Iida’s research team has focused on the low cost and environmentally friendly silicon.
They have successfully managed to mass produce Magnesium silicide (Mg2Si), from the by-product of Si-LSI and solar cell cast wafer production, providing high-performance in power generation driven by wasted heat.
- Progress of Research -
Discovery of Magnesium silicide, material for Thermoelectric Conversion driven by Wasted Heat
Heretofore the compound of Lead and Tellurium (Pb-Te), have been known to be the material for thermoelectric conversion from wasted heat. However, Lead being hazardous and Tellurium being scarce, development of new material of low environmental burden was hoped for. Iida’s research team has been successful in being pioneers of mass producing Magnesium silicide from Silicon which is found abundantly on earth, holding the characteristic of being nonhazardous. Through this discovery of environmentally benign material, the realization of an environmentally benign technology of thermoelectric conversion through wasted heat was made possible.
Development of Magnesium silicide from Silicon by-product Silicon, being the main raw material for Magnesium silicide, is widely known to be a necessary ingredient for semiconductors throughout the electronic industry. However, in production of ultrapure silicon, much energy is consumed and more than half of the material comes out as Silicon sludge, usually being disposed of. This not only pollutes the environment, but raises the cost of production and also prevents further development of new materials and/or technology.
The research team has been successful in mass producing material for thermoelectric conversion through this waste product at a substantially low cost. Through this, thermoelectric conversion from wasted heat has become even more environmentally benign.
Profile - Tsutomu Iida
Background:
March, 1995: Meiji University Graduate School – completed PhD course
April, 1995: Japan Society for the Promotion of Science – Fellowship
July, 1995: Federal Republic of Germany – Volkswagen Foundation
April, 1997: Tokyo University of Science - Faculty of Industrial
Science and Technology – Materials Science and Technology
To Present
Major Field: Semiconductor Material Engineering
Field of Research: Semiconductor Energy Material (Thermoelectric Material / Solar Cell Material) ‘Environmentally Friendly’ Semiconductor Material
Research Content: Due to mass consumption of fossil fuel and also
for prevention of global warming, research and development of energy conversion materials are being conducted. Solar energy being the main source of reusable energy, development of solar cell material and thermoelectric conversion material is being conducted. Due to the fact that many elemental devices which are used for energy conversion tending to be toxic, development of environmentally benign semiconductor energy material continues to be conducted. Environmentally benign semiconductors are composed of semiconductor material which abundantly exists on earth and is highly ‘earth-friendly’.
Research Content:
1. Development of Thermoelectric Conversion Elemental Device through Magnesium silicide
2. Development of High Efficiency Solar Cells through Silicon Germanium
3. Photodecomposition and Hydrogen Composition of water through Semiconductor Photocatalyst
Website:http://web.mac.com/iida_lab/
Contact for this information -
Tokyo University of Science Technology Licensing Organization
Administrator: Niki
TEL: 03-5225-1089
e-mail:niki_tamotsu@admin.tus.ac.jp
Indus Script Encodes Language, Reveals New Study of Ancient Symbols
The Rosetta Stone allowed 19th century scholars to translate symbols left by an ancient civilization and thus decipher the meaning of Egyptian hieroglyphics.
But the symbols found on many other ancient artifacts remain a mystery, including those of a people that inhabited the Indus valley on the present-day border between Pakistan and India. Some experts question whether the symbols represent a language at all, or are merely pictograms that bear no relation to the language spoken by their creators.
A University of Washington computer scientist has led a statistical study of the Indus script, comparing the pattern of symbols to various linguistic scripts and nonlinguistic systems, including DNA and a computer programming language. The results, published online Thursday by the journal Science, found the Indus script's pattern is closer to that of spoken words, supporting the hypothesis that it codes for an as-yet-unknown language.
"We applied techniques of computer science, specifically machine learning, to an ancient problem," said Rajesh Rao, a UW associate professor of computer science and engineering and lead author of the study. "At this point we can say that the Indus script seems to have statistical regularities that are in line with natural languages."
Co-authors are Nisha Yadav and Mayank Vahia at the Tata Institute of Fundamental Research in Mumbai, India; Hrishikesh Joglekar, a software engineer from Mumbai; R. Adhikari at the Institute of Mathematical Sciences in Chennai, India; and Iravatham Mahadevan at the Indus Research Center in Chennai. The research was supported by the Packard Foundation and the Sir Jamsetji Tata Trust.
The Indus people were contemporaries of the Egyptian and Mesopotamian civilizations, inhabiting the Indus river valley in present-day eastern Pakistan and northwestern India from about 2600 to 1900 B.C. This was an advanced, urbanized civilization that left written symbols on tiny stamp seals, amulets, ceramic objects and small tablets.
"The Indus script has been known for almost 130 years," said Rao, an Indian native with a longtime personal interest in the subject. "Despite more than 100 attempts, it has not yet been deciphered. The underlying assumption has always been that the script encodes language."
In 2004 a provocative paper titled The Collapse of the Indus-Script Thesis claimed that the short inscriptions have no linguistic content and are merely brief pictograms depicting religious or political symbols. That paper's lead author offered a $10,000 reward to anybody who could produce an Indus artifact with more than 50 symbols.
Taking a scientific approach, the U.S.-Indian team of computer scientists and mathematicians looked at the statistical patterns in sequences of Indus symbols. They calculated the amount of randomness allowed in choosing the next symbol in a sequence. Some nonlinguistic systems display a random pattern, while others, such as pictures that represent deities, follow a strict order that reflects some underlying hierarchy. Spoken languages tend to fall between the two extremes, incorporating some order as well as some flexibility.
The new study compared a well-known compilation of Indus texts with linguistic and nonlinguistic samples. The researchers performed calculations on present-day texts of English; texts of the Sumerian language spoken in Mesopotamia during the time of the Indus civilization; texts in Old Tamil, a Dravidian language originating in southern India that some scholars have hypothesized is related to the Indus script; and ancient Sanskrit, one of the earliest members of the Indo-European language family. In each case the authors calculated the conditional entropy, or randomness, of the symbols' order.
They then repeated the calculations for samples of symbols that are not spoken languages: one in which the placement of symbols was completely random; another in which the placement of symbols followed a strict hierarchy; DNA sequences from the human genome; bacterial protein sequences; and an artificially created linguistic system, the computer programming language Fortran.
Results showed that the Indus inscriptions fell in the middle of the spoken languages and differed from any of the nonlinguistic systems.
If the Indus symbols are a spoken language, then deciphering them would open a window onto a civilization that lived more than 4,000 years ago. The researchers hope to continue their international collaboration, using a mathematical approach to delve further into the Indus script.
"We would like to make as much headway as possible and ideally, yes, we'd like to crack the code," Rao said. "For now we want to analyze the structure and syntax of the script and infer its grammatical rules. Someday we could leverage this information to get to a decipherment, if, for example, an Indus equivalent of the Rosetta Stone is unearthed in the future."
More information about the Indus civilization and language is at http://www.harappa.com
The Rosetta Stone allowed 19th century scholars to translate symbols left by an ancient civilization and thus decipher the meaning of Egyptian hieroglyphics.
But the symbols found on many other ancient artifacts remain a mystery, including those of a people that inhabited the Indus valley on the present-day border between Pakistan and India. Some experts question whether the symbols represent a language at all, or are merely pictograms that bear no relation to the language spoken by their creators.
A University of Washington computer scientist has led a statistical study of the Indus script, comparing the pattern of symbols to various linguistic scripts and nonlinguistic systems, including DNA and a computer programming language. The results, published online Thursday by the journal Science, found the Indus script's pattern is closer to that of spoken words, supporting the hypothesis that it codes for an as-yet-unknown language.
"We applied techniques of computer science, specifically machine learning, to an ancient problem," said Rajesh Rao, a UW associate professor of computer science and engineering and lead author of the study. "At this point we can say that the Indus script seems to have statistical regularities that are in line with natural languages."
Co-authors are Nisha Yadav and Mayank Vahia at the Tata Institute of Fundamental Research in Mumbai, India; Hrishikesh Joglekar, a software engineer from Mumbai; R. Adhikari at the Institute of Mathematical Sciences in Chennai, India; and Iravatham Mahadevan at the Indus Research Center in Chennai. The research was supported by the Packard Foundation and the Sir Jamsetji Tata Trust.
The Indus people were contemporaries of the Egyptian and Mesopotamian civilizations, inhabiting the Indus river valley in present-day eastern Pakistan and northwestern India from about 2600 to 1900 B.C. This was an advanced, urbanized civilization that left written symbols on tiny stamp seals, amulets, ceramic objects and small tablets.
"The Indus script has been known for almost 130 years," said Rao, an Indian native with a longtime personal interest in the subject. "Despite more than 100 attempts, it has not yet been deciphered. The underlying assumption has always been that the script encodes language."
In 2004 a provocative paper titled The Collapse of the Indus-Script Thesis claimed that the short inscriptions have no linguistic content and are merely brief pictograms depicting religious or political symbols. That paper's lead author offered a $10,000 reward to anybody who could produce an Indus artifact with more than 50 symbols.
Taking a scientific approach, the U.S.-Indian team of computer scientists and mathematicians looked at the statistical patterns in sequences of Indus symbols. They calculated the amount of randomness allowed in choosing the next symbol in a sequence. Some nonlinguistic systems display a random pattern, while others, such as pictures that represent deities, follow a strict order that reflects some underlying hierarchy. Spoken languages tend to fall between the two extremes, incorporating some order as well as some flexibility.
The new study compared a well-known compilation of Indus texts with linguistic and nonlinguistic samples. The researchers performed calculations on present-day texts of English; texts of the Sumerian language spoken in Mesopotamia during the time of the Indus civilization; texts in Old Tamil, a Dravidian language originating in southern India that some scholars have hypothesized is related to the Indus script; and ancient Sanskrit, one of the earliest members of the Indo-European language family. In each case the authors calculated the conditional entropy, or randomness, of the symbols' order.
They then repeated the calculations for samples of symbols that are not spoken languages: one in which the placement of symbols was completely random; another in which the placement of symbols followed a strict hierarchy; DNA sequences from the human genome; bacterial protein sequences; and an artificially created linguistic system, the computer programming language Fortran.
Results showed that the Indus inscriptions fell in the middle of the spoken languages and differed from any of the nonlinguistic systems.
If the Indus symbols are a spoken language, then deciphering them would open a window onto a civilization that lived more than 4,000 years ago. The researchers hope to continue their international collaboration, using a mathematical approach to delve further into the Indus script.
"We would like to make as much headway as possible and ideally, yes, we'd like to crack the code," Rao said. "For now we want to analyze the structure and syntax of the script and infer its grammatical rules. Someday we could leverage this information to get to a decipherment, if, for example, an Indus equivalent of the Rosetta Stone is unearthed in the future."
More information about the Indus civilization and language is at http://www.harappa.com
Thursday, April 23, 2009
New Family of Proteins - TPC2
International research collaborators have identified a new family of proteins, TPC2 (two-pore channels), that facilitates calcium signaling from specialized subcellular organelles. It is the first to isolate TPC2 as a channel that binds to nucleotide nicotinic acid adenine dinucleotide phosphate (NAADP), a second-signaling messenger, resulting in the release of calcium from intracellular stores. According to the researchers, this new discovery may have broad implications in cell biology and human disease research.
“The discovery was the result of many researchers working as one international team toward a unified outcome. We are very appreciative of all the collaborators’ efforts,” said Jianjie Ma, PhD, professor of physiology and biophysics at UMDNJ-Robert Wood Johnson Medical School. “We are proud to be part of a study that will stand as the foundation for further exploration of human disease, helping researchers to better understand how calcium contributes to cell growth and disorders, including aging-related cardiac disease, diabetes, lysosomal cell dysfunction and the metastasis of cells in cancer.”
According to the researchers, the mechanism for how NAADP triggers the release of calcium, as well as the specific sites of calcium store targeted for release, were previously unknown. These findings indicate that NAADP, through its interaction with TPC2, targets a specific store of calcium in lysosomes, a specialized subunit within the cell that contain digestion enzymes and regulate cell function.
The study was a collaboration of investigative teams at four universities, including the laboratory of Dr. Michael Zhu at the Ohio State University, the laboratory of Dr. A. Mark Evans at the University of Edinburgh and the laboratory of Dr. Antony Galione at the University of Oxford.
The research was supported by grants from the United Kingdom’s Wellcome Trust and the British Heart Foundation, the United States’ National Institutes of Health, and the American Heart Association.
UMDNJ-ROBERT WOOD JOHNSON MEDICAL SCHOOL
As one of the nation’s leading comprehensive medical schools, Robert Wood Johnson Medical School of the University of Medicine and Dentistry of New Jersey is dedicated to the pursuit of excellence in education, research, health care delivery, and the promotion of community health. In cooperation with Robert Wood Johnson University Hospital, the medical school’s principal affiliate, they comprise New Jersey’s premier academic medical center. In addition, Robert Wood Johnson Medical School has 34 hospital affiliates and ambulatory care sites throughout the region.
As one of the eight schools of the University of Medicine and Dentistry of New Jersey with 2,800 full-time and volunteer faculty, Robert Wood Johnson Medical School encompasses 22 basic science and clinical departments and hosts centers and institutes including The Cancer Institute of New Jersey, the Child Health Institute of New Jersey, the Center for Advanced Biotechnology and Medicine, the Environmental and Occupational Health Sciences Institute, and the Stem Cell Institute of New Jersey. The medical school maintains educational programs at the undergraduate, graduate and postgraduate levels for more than 1,500 students on its campuses in New Brunswick, Piscataway, and Camden, and provides continuing education courses for health care professionals and community education programs.
International research collaborators have identified a new family of proteins, TPC2 (two-pore channels), that facilitates calcium signaling from specialized subcellular organelles. It is the first to isolate TPC2 as a channel that binds to nucleotide nicotinic acid adenine dinucleotide phosphate (NAADP), a second-signaling messenger, resulting in the release of calcium from intracellular stores. According to the researchers, this new discovery may have broad implications in cell biology and human disease research.
“The discovery was the result of many researchers working as one international team toward a unified outcome. We are very appreciative of all the collaborators’ efforts,” said Jianjie Ma, PhD, professor of physiology and biophysics at UMDNJ-Robert Wood Johnson Medical School. “We are proud to be part of a study that will stand as the foundation for further exploration of human disease, helping researchers to better understand how calcium contributes to cell growth and disorders, including aging-related cardiac disease, diabetes, lysosomal cell dysfunction and the metastasis of cells in cancer.”
According to the researchers, the mechanism for how NAADP triggers the release of calcium, as well as the specific sites of calcium store targeted for release, were previously unknown. These findings indicate that NAADP, through its interaction with TPC2, targets a specific store of calcium in lysosomes, a specialized subunit within the cell that contain digestion enzymes and regulate cell function.
The study was a collaboration of investigative teams at four universities, including the laboratory of Dr. Michael Zhu at the Ohio State University, the laboratory of Dr. A. Mark Evans at the University of Edinburgh and the laboratory of Dr. Antony Galione at the University of Oxford.
The research was supported by grants from the United Kingdom’s Wellcome Trust and the British Heart Foundation, the United States’ National Institutes of Health, and the American Heart Association.
UMDNJ-ROBERT WOOD JOHNSON MEDICAL SCHOOL
As one of the nation’s leading comprehensive medical schools, Robert Wood Johnson Medical School of the University of Medicine and Dentistry of New Jersey is dedicated to the pursuit of excellence in education, research, health care delivery, and the promotion of community health. In cooperation with Robert Wood Johnson University Hospital, the medical school’s principal affiliate, they comprise New Jersey’s premier academic medical center. In addition, Robert Wood Johnson Medical School has 34 hospital affiliates and ambulatory care sites throughout the region.
As one of the eight schools of the University of Medicine and Dentistry of New Jersey with 2,800 full-time and volunteer faculty, Robert Wood Johnson Medical School encompasses 22 basic science and clinical departments and hosts centers and institutes including The Cancer Institute of New Jersey, the Child Health Institute of New Jersey, the Center for Advanced Biotechnology and Medicine, the Environmental and Occupational Health Sciences Institute, and the Stem Cell Institute of New Jersey. The medical school maintains educational programs at the undergraduate, graduate and postgraduate levels for more than 1,500 students on its campuses in New Brunswick, Piscataway, and Camden, and provides continuing education courses for health care professionals and community education programs.
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