Scientists learn how horseweed shrugs off herbicide
As everyone knows, the pharmaceutical industry is struggling to deal with bacteria that have become resistant to common antibiotics. Less well known is the similar struggle in agribusiness to deal with weeds that have become resistant to a herbicide that is widely used in farming practice. The herbicide, first introduced in 1974, is glyphosate, the active ingredient in Monsanto's Roundup products and also in herbicides produced by other manufacturers. The first case of glyphosate resistance was documented in 1997, and today more than 20 weed species globally are reported to be resistant. (For more on the history of the herbicide read "The Back Story" here.)
Recently a team of scientists from Washington University in St. Louis and Monsanto, the St. Louis-based company that makes Roundup herbicides, were able to follow molecules of glyphosate as they entered a resistant variant of horseweed to discover exactly how the plant disarms the herbicide. Their work was published in Pest Management Science last year.
In a second paper published in April 2011, also in Pest Management Science, they describe herbicide application conditions that can be used to overcome the resistance mechanism they had discovered.
This is not the end of the story, the scientists say, because some weed species are resistant to the herbicide in ways different from horseweed. Still the scientists are glad to have won this round even if they know the contest will be prolonged.
Caught in the act
"The story begins when I received a phone call from Doug Sammons, who directs a research group at Monsanto tasked with uncovering the mechanisms leading to glyphosate resistance in weed species," says D. André d'Avignon, PhD, director of Washington University's High Resolution Nuclear Magnetic Resonance Facility.
"He was calling because, under favorable conditions, it is possible to track the chemical fate of phosphorus in a living system with nuclear magnetic resonance (NMR)," says d'Avignon. (As its name implies, glyphosate consists of a phosphonate group (PO3) attached to the amino acid glycine.)
"I was initially very skeptical," says d'Avignon. "My feeling was that, because a living plant would present a very heterogeneous environment, we would not observe well-resolved phosphorus NMR signals from glyphosate, let alone pinpoint glyphosate's cellular handling.
"I was proved wrong," he says.
To attack the problem, d'Avignon assembled a team of chemists skilled in the field of NMR. Along with Sammons from Monsanto, he enlisted Xia Ge, PhD, a postdoctoral research associate, and Joseph Ackerman, PhD, the William Greenleaf Eliot Professor of Chemistry in Arts & Sciences.
Simple Chemistry Experiments - News
Along with Sammons from Monsanto, he enlisted Xia Ge, PhD, a postdoctoral research associate, and Joseph Ackerman, PhD, the William Greenleaf Eliot Professor of Chemistry in Arts & Sciences. D'Avignon's team focused its initial efforts on Conyza
To find out if the sediment contained anything that could survive and grow using arsenic rather than phosphorus, she mixed lake sediment with a simple culture medium. The medium had the same basic chemical properties as the lake water but also provided
'Water at high temperature is a beneficial solvent. Our experiments have shown that catalysts can be simplified under such conditions,' he says. 'Saving catalysts by employing high temperature and simple salts adds another sustainable feature.
By hearing these experiments that we feel have worked, I think that it's opened up new doors for us in songwriting. Who sang the part of the character named Veronica? The character of Veronica actually had her voice broken up between two people.
Protein Chemistry: Fluorescence method reveals details of disease-related process. Toxic Substances: Scientists detect the endocrine disrupter in the food and urine of young children. Industry livelihood and modern conveniences versus uncompromised
high school textbook for chemistry-Illustrated Guide to Home ...
Are you a frustrated chemist who never outgrew their fascination with the home chemistry kits of the good old days? Back when people took responsibility for their actions and “product liability” wasn’t the fear of every company out there? This is the EXACT book you need to get in order to rekindle that love or to pass it on to a new generation… Illustrated Guide to Home Chemistry Experiments: All Lab, No Lecture by Robert Bruce Thompson. You won’t get a simple “isn’t it cool how this changes color?” approach to science. Thompson covers serious stuff, complete with best practices, methodologies for recording your experiments, and plenty of safety tips along the way. After working through this book, you’ll be further ahead than most entry-level college students.
Contents: Introduction; Laboratory Safety; Equipping a Home Chemistry Lab; Chemicals for the Home Chemistry Lab; Mastering Laboratory Skills; Separating Mixtures; Solubility and Solutions; Colligative Properties of Solutions; Introduction to Chemical Reactions and Stoichiometry; Reduction-Oxidation (Redox) Reactions; Acid-Base Chemistry; Chemical Kinetics; Chemical Equilibrium and Le Chatelier’s Principle; Gas Chemistry; Thermochemistry and Calorimetry; Electrochemistry; Photochemistry; Colloids and Suspensions; Qualitative Analysis; Quantitative Analysis; Synthesis of Useful Compounds; Forensic Chemistry; Index
I *did* say it was far more than just changing the colors of liquids in a test tube…
You can tell that Thompson has a real love of this field. He starts off with his story of how he got interested in chemistry, as well as how this book would map to a first or second year chemistry course. He explains the value of keeping a laboratory notebook in a way that will meticulously track your results and offer a chain of evidence should you stumble upon the next great compound. Safety and supplies follow that, and he does an excellent job in balancing risk and reward, cost and budget. Instead of just saying that you should avoid anything that can possibly injure you, he advises you on how to protect yourself, how to safely handle chemicals that could react in a dangerous fashion, and generally do what you need to do without fearing every little step. After the supplies, you get a course in the chemicals you’ll need to obtain to do many of these experiments. Some are fairly easy to get, while others have become more controlled and restricted over the years. Still, he points you to sources and alternatives that will keep this from becoming an overly expensive habit. After a final chapter on laboratory skills, you start getting into the good stuff… mixing chemicals to observe reactions!
Simple Chemistry Experiments - Bookshelf
Chemistry experiments for children
Gives directions for many simple chemistry experiments, including descriptions of necessary equipment, principles, techniques, and safety precautions.Simple chemistry experiments with everyday materials
Illustrated guide to home chemistry experiments, all lab, no lecture
Provides information on setting up an in-home chemistry lab, covers the basics of chemistry, and offers a variety of experiments.Classic chemistry experiments
This collection of 100 chemistry experiments has been developed with the help and support of teachers throughout the UK. Each student worksheet is accompanied ...Chemistry Experiments
Provides instructions for chemistry experiments using common household items, including working with air and water, salt and sugar, crystals, foods and other ...Day-by-day Info Directory
Chemistry Experiments & Demonstrations You Can Do at Home
Here are some do-it-at-home chemistry experiments. Some are for home schooling, some are for fun, some involve cooking, and some are ill-advised.
Chemistry Demonstrations, Chemistry Experiments, Chemistry ...
These are tutorials for performing your own chemistry demonstrations, laboratory exercises, projects, and experiments. Photos and movies are available for some demos.
Science Is Fun Home Experiments
The answer seems obvious, but this experiment will show otherwise. ... some home experiments from friends of Professor Shakhashiri. SOME SIMPLE SCIENCE WITH ...
High School Chemistry Experiments!
High School Chemistry ... Experiments must be reproducible; they should fail the same way each time. First draw your curves, and then plot your data. ...
Experiments with Acids and Bases
Article on the realisation of experiments on acids and bases. ... This time, we will do some simple chemistry experiments to begin learning about acids and bases. ...