Organic food reduces pesticide exposure

 

While health-conscious individuals understand the benefits of eating fresh fruits and veggies, they may not be aware of the amount of pesticides they could be ingesting along with their vitamin C and fiber. A new study to be published in the Feb. 5 edition of Environmental Health Perspectives is among the first to predict a person's pesticide exposure based on information about their usual diet. The study was led by Cynthia Curl, an assistant professor in Boise State University's School of Allied Health Sciences. She recently joined Boise State from the University of Washington. Curl and her colleagues analyzed the dietary exposure of nearly 4,500 people from six U.S. cities to organophosphates (OPs), the most common insecticides used on conventionally grown produce in the United States. OP pesticides are linked to a number of detrimental health effects, particularly among agricultural workers who are regularly exposed to the chemicals. Results showed that among individuals eating similar amounts of fruits and vegetables, those who reported eating organic produce had significantly lower OP pesticide exposures than those consuming conventionally grown produce. In addition, consuming those conventionally grown foods typically treated with more of these pesticides during production, including apples, nectarines and peaches, was associated with significantly higher levels of exposure. "For most Americans, diet is the primary source of OP pesticide exposure," said Curl "The study suggests that by eating organically grown versions of those foods highest in pesticide residues, we can make a measurable difference in the levels of pesticides in our bodies." This study included dietary data collected from participants in the Multi-Ethnic Study of Atherosclerosis, a large, multi-institutional project funded by the National Heart, Lung and Blood Institute that is investigating factors that influence the onset of cardiovascular disease. The researchers were able to predict each participant's exposure to OP pesticides based on the amount and type of produce each participant typically ate and the U.S. Department of Agriculture's measurements of pesticide residue levels on those foods. The researchers then compared these predictions to pesticide metabolite levels measured in urine samples from a subset of 720 of these people. While Curl's study is not the first to link organic produce with reduced pesticide exposure, the method she used may have significant implications for future research. By combining self-reported information on typical food consumption with USDA measurements, researchers will be able to conduct research on the relationship between dietary pesticide exposure and health outcomes in bigger populations, without needing to measure urinary metabolites. "If we can predict pesticide exposure using dietary questionnaire data, then we may be able to understand the potential health effects of dietary exposure to pesticides without having to collect biological samples from people," Curl said. "That will allow research on organic food to be both less expensive and less invasive." "The next step is to use these exposure predictions to examine the relationship between dietary exposure to pesticides and health outcomes, including neurological and cognitive endpoints. We'll be able to do that in this same population of nearly 4,500 people," she said. One way people can reduce their pesticide exposure, said Curl, is to eat organic versions of those foods that are listed on the Environmental Working Group's "Dirty Dozen" list, which ranks fruits and vegetables according to pesticide residue level. Story Source: The above story is based on materials provided by Boise State University. Note: Materials may be edited for content and length. Journal Reference: Cynthia L. Curl, Shirley A. A. Beresford, Richard A. Fenske, Annette L. Fitzpatrick, Chensheng Lu, Jennifer A. Nettleton, Joel D. Kaufman. Estimating Pesticide Exposure from Dietary Intake and Organic Food Choices: The Multi-Ethnic Study of Atherosclerosis (MESA). Environmental Health Perspectives, 2015; DOI: 10.1289/ehp.1408197

Cheap and abundant chemical outperforms precious metals as a catalyst

 

"We have shown for the first time that you can efficiently make carbon-silicon bonds with a safe and inexpensive catalyst based on potassium rather than ultrarare precious metals like platinum, palladium, and iridium," says Anton Toutov, a graduate student working in the laboratory of Bob Grubbs, Caltech's Victor and Elizabeth Atkins Professor of Chemistry. "We're very excited because this new method is not only 'greener' and more efficient, but it is also thousands of times less expensive than what's currently out there for making useful chemical building blocks. This is a technology that the chemical industry could readily adopt." The finding marks one of the first cases in which catalysis -- the use of catalysts to make certain reactions occur faster, more readily, or at all -- moves away from being a practice that is fundamentally unsustainable. While the precious metals in most catalysts are rare and could eventually run out, potassium is an abundant element on Earth. The team describes its new "green" chemistry technique in the February 5 issue of the journal Nature. The lead authors on the paper are Toutov and Wen-bo (Boger) Liu, a postdoctoral scholar at Caltech. Toutov recently won the Dow Sustainability Innovation Student Challenge Award (SISCA) grand prize for this work, in a competition held at Caltech's Resnick Sustainability Institute. "The first time I spoke about this at a conference, people were stunned," says Grubbs, corecipient of the 2005 Nobel Prize in Chemistry. "I added three slides about this chemistry to the end of my talk, and afterward it was all anyone wanted to talk about." Coauthor Brian Stoltz, professor of chemistry at Caltech, says the reason for this strong response is that while the chemistry the catalyst drives is challenging, potassium tert-butoxide is so seemingly simple. The white, free-flowing powder -- similar to common table salt in appearance -- provides a straightforward and environmentally friendly way to run a reaction that involves replacing a carbon-hydrogen bond with a carbon-silicon bond to produce molecules known as organosilanes. These organic molecules are of particular interest because they serve as powerful chemical building blocks for medicinal chemists to use in the creation of new pharmaceuticals. They also hold promise in the development of new materials for use in products such as LCD screens and organic solar cells, could be important in the development of new pesticides, and are being incorporated into novel medical imaging tools. "To be able to do this type of reaction, which is one of the most-studied problems in the world of chemistry, with potassium tert-butoxide -- a material that's not precious-metal based but still catalytically active -- was a total shocker," Stoltz says. The current project got its start a couple of years ago when coauthor Alexey Fedorov -- then a postdoctoral scholar in the Grubbs lab (now at ETH Zürich) -- was working on a completely different problem. He was trying to break carbon-oxygen bonds in biomass using simple silicon-containing compounds, metals, and potassium tert-butoxide, which is a common additive. During that process, he ran a control experiment -- one without a metal catalyst -- leaving only potassium tert-butoxide as the reagent. Remarkably, the reaction still worked. And when Toutov -- who was working with Fedorov -- analyzed the reaction further, he realized that in addition to the expected products, the reaction was making small amounts of organosilanes. This was unexpected since organosilanes are very challenging to produce. "I thought that was impossible, so I went back and checked it many times," Toutov says. "Sure enough, it checked out!" Bolstered by the finding, Toutov refined the reaction so that it would create only a single desired organosilane in high yield under mild conditions, with hydrogen gas as the only byproduct. Then he expanded the scope of the reaction to produce industrially useful chemicals such as molecules needed for new materials and derivatives of pharmaceutical substances. Having demonstrated the broad applicability of the reaction, Toutov teamed up with Liu from Stoltz's group to further develop the chemistry for the synthesis of building blocks relevant to the preparation of new human medicines, a field in which Stoltz has been active for over a decade. But before delving too deeply into additional applications, the chemists sought the assistance of Nathan Dalleska, director of the Environmental Analysis Center in the Ronald and Maxine Linde Center for Global Environmental Science at Caltech to perform one more test with a mass spectrometer that geologists use to detect extremely minute quantities of metals. They were trying to detect some tiny amount of those precious metals that could be contaminating their experiments -- something that might explain why they were getting these seemingly impossible results from potassium tert-butoxide alone. "But there was nothing there," says Stoltz. "We made our own potassium tert-butoxide and also bought it from various vendors, and yet the chemistry continued to work just the same. We had to really convince ourselves that it was true, that there were no precious metals in there. Eventually, we had to just decide to believe it." So far, the chemists do not know why the simple catalyst is able to drive these complex reactions. But Stoltz's lab is part of the Center for Selective C-H Functionalization, a National Science Foundation-funded Center for Chemical Innovation that involves 23 research groups from around the country. Through that center, the Caltech team has started working with Ken Houk's computational chemistry group at UCLA to investigate how the chemistry works from a mechanistic standpoint. "It's pretty clear that it's functioning by a mechanism that is totally different than the way a precious metal would behave," says Stoltz. "That's going to inspire some people, including ourselves hopefully, to think about how to use and harness that reactivity." Toutov says that unlike some other catalysts that stop working or become sensitive to air or water when scaled up from the single-gram scale, this new catalyst seems to be robust enough to be used at large, industrial scales. To demonstrate the industrial viability of the process, the Caltech team used the method to synthesize nearly 150 grams of a valuable organosilane -- the largest amount of this chemical product that has been produced by a single catalytic reaction. The reaction required no solvent, generated hydrogen gas as the only byproduct, and proceeded at 45°C -- the lowest reported temperature at which this reaction has successfully run, to date. "This discovery just shows how little we in fact know about chemistry," says Stoltz. "People constantly try to tell us how mature our field is, but there is so much fundamental chemistry that we still don't understand." Kerry Betz, an undergraduate student at Caltech, is a coauthor on the paper, "Silylation of C-H bonds in aromatic heterocycles by an Earth-abundant metal catalyst." The work was supported by the National Science Foundation. The Resnick Sustainability Institute at Caltech, Dow Chemical, the Natural Sciences and Engineering Research Council of Canada, and the Shanghai Institute of Organic Chemistry provided graduate and postdoctoral support. Federov's work on the original reaction was supported by BP.

Scientists predict Earth-like planets around most stars

 

Planetary scientists have calculated that there are hundreds of billions of Earth-like planets in our galaxy which might support life. Planetary scientists have calculated that there are hundreds of billions of Earth-like planets in our galaxy which might support life. The new research, led by PhD student Tim Bovaird and Associate Professor Charley Lineweaver from The Australian National University (ANU), made the finding by applying a 200-year-old idea to the thousands of exo-planets discovered by the Kepler space telescope. They found the standard star has about two planets in the so-called Goldilocks zone, the distance from the star where liquid water, crucial for life, can exist. "The ingredients for life are plentiful, and we now know that habitable environments are plentiful," said Associate Professor Lineweaver, from the ANU Research School of Astronomy and Astrophysics and the Research School of Earth Sciences. "However, the universe is not teeming with aliens with human-like intelligence that can build radio telescopes and space ships. Otherwise we would have seen or heard from them. "It could be that there is some other bottleneck for the emergence of life that we haven't worked out yet. Or intelligent civilisations evolve, but then self-destruct." The Kepler space telescope is biased towards seeing planets very close to their stars, that are too hot for liquid water, but the team extrapolated from Kepler's results using the theory that was used to predict the existence of Uranus. "We used the Titius-Bode relation and Kepler data to predict the positions of planets that Kepler is unable to see," Associate Professor Lineweaver said. Story Source: The above story is based on materials provided by Australian National University. Note: Materials may be edited for content and length. Journal Reference: Timothy Bovaird, Charles H. Lineweaver, Steffen K. Jacobsen. Using the Inclinations of Kepler Systems to Prioritize New Titius-Bode-Based Exoplanet Predictions. Monthly Notices of the Royal Astronomical Society, 2015 [link]

Faster first aid for catastrophe victims

 

February 3, 2015 Fraunhofer-Institut fuer Angewandte Informationstechnik (FIT) A new system aims to speed up the triage of victims during mass casualty incidents: Instead of colored paper tags, first responders use colored electronic wristbands. These serve to locate victims and transmit vital data to emergency response control centers. An app for Android smartphones also lets victims buried alive under a collapsed building contact rescue teams even though mobile phone networks are down. Instead of colored paper tags, first responders use colored electronic wristbands. A new system aims to speed up the triage of victims during mass casualty incidents: Instead of colored paper tags, first responders use colored electronic wristbands. These serve to locate victims and transmit vital data to emergency response control centers. FIT also demonstrates an app for Android smartphones that lets victims buried alive under a collapsed building contact rescue teams even though mobile phone networks are down. Visit us at CeBIT, March 16 – 20, 2015, Hall 9, E40. In mass casualty incidents, triage of the victims must be performed as quickly as possible, in order to evacuate and take them to appropriate hospitals. Today, first responders use colored paper tags to classify victims. In cooperation with an international group of partners, Fraunhofer FIT has developed an electronic gadget that may replace the colored paper tags in a triage. Beyond just visually tagging a victim, the device transmits, in real time, the victim's location and vital data, e.g. heart rate, respiratory rate and oxygen saturation, to emergency response control centers. The first responders attach a color-coded plastic wristband to each victim. Depending on their color, the wristbands incorporate different sets of technology, e.g. a GPS module, an RFID chip and a wireless network module that communicates with the emergency response control center. An unharmed or slightly injured person will receive a wristband that includes only the GPS and the network module. Victims severely injured or in a critical state will receive wristbands with additional sensors that continually capture vital data and transmit them to the control center. Each wristband also functions as a node in a wireless network. Even if the regular mobile phone networks are down, our system is still operational. It sets up an ad-hoc ZigBee network, a low-bandwidth wireless network that combines long range and low energy consumption. The wristbands have the necessary technology built in. First responders get equipped with Triage Relays that cache, backup and retransmit the data. "The real-time data from the triage wrsitbands can be displayed on the large screens in the emergency response control center, but also on the tablets or smartphones of medical staff in the field. First responders and response coordinators thus have a precise picture of the situation on the ground. Rescuers see at a glance where the majority of severely injured casualties are located and can direct the rescue activities accordingly", explains Dr. René Reiners, project manager at Fraunhofer FIT. The system was developed in the European BRIDGE project (www.bridgeproject.eu) where FIT's User-Centered Computing department (headed by Dr. Markus Eisenhauer) is the technical coordinator. FIT will also demonstrate a pair of smartphone apps that lets victims communicate with first responders even if the mobile phone networks are down. One component of the solution is an app on the victim's smartphone. When the user activates it, it sets up a Wi-Fi access point and sends an emergency message, e.g. "Buried Alive", instead of the phone's regular Wi-Fi Service Identifier (SSID). The app on the first responder's phone scans for WLAN networks in its vicinity, detects the emergency message and sends a response signal to the victim's app. The solution we demonstrate uses stock Android smartphones that give it a range of up to 100 meters. Story Source: The above story is based on materials provided by Fraunhofer-Institut fuer Angewandte Informationstechnik (FIT). Note: Materials may be edited for content and length.

Compound found in grapes, red wine may help prevent memory loss

 

A compound found in common foods such as red grapes and peanuts may help prevent age-related decline in memory, according to new research published by a faculty member in the Texas A&M Health Science Center College of Medicine. Ashok K. Shetty, Ph.D., a professor in the Department of Molecular and Cellular Medicine and Director of Neurosciences at the Institute for Regenerative Medicine, has been studying the potential benefit of resveratrol, an antioxidant that is found in the skin of red grapes, as well as in red wine, peanuts and some berries. Resveratrol has been widely touted for its potential to prevent heart disease, but Shetty and a team that includes other researchers from the health science center believe it also has positive effects on the hippocampus, an area of the brain that is critical to functions such as memory, learning and mood. Because both humans and animals show a decline in cognitive capacity after middle age, the findings may have implications for treating memory loss in the elderly. Resveratrol may even be able to help people afflicted with severe neurodegenerative conditions such as Alzheimer's disease. In a study published online Jan. 28 in Scientific Reports, Shetty and his research team members reported that treatment with resveratrol had apparent benefits in terms of learning, memory and mood function in aged rats. "The results of the study were striking," Shetty said. "They indicated that for the control rats who did not receive resveratrol, spatial learning ability was largely maintained but ability to make new spatial memories significantly declined between 22 and 25 months. By contrast, both spatial learning and memory improved in the resveratrol-treated rats." Shetty said neurogenesis (the growth and development of neurons) approximately doubled in the rats given resveratrol compared to the control rats. The resveratrol-treated rats also had significantly improved microvasculature, indicating improved blood flow, and had a lower level of chronic inflammation in the hippocampus. "The study provides novel evidence that resveratrol treatment in late middle age can help improve memory and mood function in old age," Shetty said. This study was funded primarily by the National Center for Complementary and Alternative Medicine (NCCAM) at the National Institutes of Health. Shetty's lab is now examining the molecular mechanisms that underlie the improved cognitive function following resveratrol treatment. He also plans to conduct studies to see whether lower doses of resveratrol in the diet for prolonged periods would offer similar benefits to the aged brain. Story Source: The above story is based on materials provided by Texas A&M University. Note: Materials may be edited for content and length. Journal Reference: Maheedhar Kodali, Vipan K. Parihar, Bharathi Hattiangady, Vikas Mishra, Bing Shuai, Ashok K. Shetty. Resveratrol Prevents Age-Related Memory and Mood Dysfunction with Increased Hippocampal Neurogenesis and Microvasculature, and Reduced Glial Activation. Scientific Reports, 2015; 5: 8075 DOI: 10.1038/srep08075