Grounds For Concern: Is Your Coffee Consistent?

UC Davis entomologist Christian Nansen trained some high-tech analysis on coffee beans, showing that brands were not consistent in content. Photo: Kathy Garvey

UC Davis entomologist Christian Nansen trained some high-tech analysis on coffee beans, showing that brands were not consistent in content. Photo: Kathy Garvey

By Kathy Keatley Garvey

If your particular brand of coffee doesn’t seem to taste the same from week to week or month to month, you may be  right. And it’s not you, it’s the coffee beans.

Agricultural entomologist Christian Nansen of the UC Davis Department of Entomology and Nematology and four colleagues analyzed 15 brands of roasted coffee beans, purchased at an area supermarket on two dates about six months apart, and using hyperspectral imaging technology, found “they were all over the board.”

Chemwiki free textbook effort expands with $600,000 grant

By Becky Oskin

College students in the STEM fields could see sizable savings thanks to a $600,000 grant awarded to an open source textbook project developed at the University of California, Davis.

The ChemWiki project recently received $600,000 from the National Science Foundation to support further expansion of its open source textbooks into fields including statistics, math, geology, physics, biology and solar energy.

Digital course materials are steadily climbing in use in response to textbook cost concerns, according to an annual survey released in July by the National Association of College Stores. In August, the University of Maryland announced plans to completely eliminate print textbooks this academic year.

Oxygen oasis in Antarctic lake reflects distant past

At the bottom of a frigid Antarctic lake, a thin layer of green slime is generating a little oasis of oxygen, a team including UC Davis researchers has found. It’s the first modern replica discovered of conditions on Earth two and a half billion years ago, before oxygen became common in the atmosphere. The discovery is reported in a paper in the journal Geology.

The switch from a planet with very little available oxygen to one with an atmosphere much like today’s was one of the major events in Earth’s history, and it was all because some bacteria evolved the ability to photosynthesize. By about 2.4 billion years ago, geochemical records show that oxygen was present all the way to the upper atmosphere, as ozone.

Finding biomarkers for early lung cancer diagnosis

Despite decades of warnings about smoking, lung cancer is still the second-most common cancer and the leading cause of death from cancer in the U.S. Patients are often diagnosed only when their disease is already at an advanced stage and hard to treat. Researchers at the West Coast Metabolomics Center at UC Davis are trying to change that, by identifying biomarkers that could be the basis of early tests for lung cancer.

“Early diagnosis is the key to fighting lung cancer,” said Oliver Fiehn, director of the metabolomics center and a professor of molecular and cellular biology at UC Davis.

Engineering new routes to biochemicals

Living cells can make a vast range of products for us, but they don’t always do it in the most straightforward or efficient way. Shota Atsumi, a chemistry professor at UC Davis, aims to address that through “synthetic biology:” designing and building new biochemical pathways within living cells, based on existing pathways from other living things.

Engineered bacteria use both glucose and acetate, instead of just glucose, as raw material to make isobutyl acetate, which can be used in chemical manufacturing and as fuel.

Engineered bacteria use both glucose and acetate, instead of just glucose, as raw material to make isobutyl acetate, which can be used in chemical manufacturing and as fuel.

Wine cork or screwcap? It depends on aging

The winter holidays have brought many occasions to celebrate with wine and notice the variety of closures now being used to seal wines. As the New Year kicks off, you may find yourself wondering which type of closure is the best and whether that choice is consistent for all wines.

Andrew Waterhouse, professor and wine chemist in the UC Davis Department Viticulture and Enology, offers some research-based advice in an article recently published in The Conversation, an online publication written by academics.

New X-ray technique for surfaces

Surfaces are very interesting to material scientists. The reactions that happen at the point where inside and outside meet, and elements interact with other chemicals or radiation, are important for developing new technology for batteries, fuel cells or photovoltaic panels, for catalysts for the chemical industry, and for understanding environmental chemistry and pollution. Now researchers at UC Davis and the Advanced Light Source at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory have combined two existing methods techniques to come up with a new method for studying surfaces with X-rays. This new technique is called SWAPPS, for Standing Wave Ambient Pressure Photoelectron Spectroscopy.

Making oxygen before life

About one-fifth of the Earth’s atmosphere is oxygen, pumped out by green plants as a result of photosynthesis and used by most living things on the planet to keep our metabolisms running. But before the first photosynthesizing organisms appeared about 2.4 billion years ago, the atmosphere likely contained mostly carbon dioxide, as is the case today on Mars and Venus.

Over the past 40 years, researchers have thought that there must have been a small amount of oxygen in the early atmosphere. Where did this abiotic (“non-life”) oxygen come from? Oxygen reacts quite aggressively with other compounds, so it would not persist for long without some continuous source.

Watching the structure of glass under pressure

Glass has many applications that call for different properties, such as resistance to thermal shock or to chemically harsh environments. Glassmakers commonly use additives such as boron oxide to tweak these properties by changing the atomic structure of glass. Now researchers at the University of California, Davis, have for the first time captured atoms in borosilicate glass flipping from one structure to another as it is placed under high pressure.

The findings may have implications for understanding how glasses and similar “amorphous” materials respond at the atomic scale under stress, said Sabyasachi Sen, professor of materials science at UC Davis. Sen is senior author on a paper describing the work published Aug. 29 in the journal Science.

Reproducing deep-Earth chemistry

A new pressure cell invented by UC Davis researchers makes it possible to simulate chemical reactions deep in the Earth’s crust. The cell allows researchers to perform nuclear magnetic resonance (NMR) measurements on as little as 10 microliters of liquid at pressures up to 20 kiloBar.

“NMR is our window into the chemical world,” said Brent Pautler, a postdoctoral researcher in chemistry at UC Davis and first author on the paper published July 2 in the online edition of the journal Angewandte Chemie. “It lets us see chemical reactions as they are happening.”