Do Zebra stripes confuse biting flies?

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Zebra stripes have fascinated people for millennia, and there are a number of different theories to explain why these wild horses should be so brightly marked. A handful of laboratories around the world – including one lead by UC Davis wildlife biologist Tim Caro – have been putting these theories to the test. A new paper from Caro’s group, led by Ken Britten at the UC Davis Center for Neuroscience, puts a hole in one idea: that the stripes confuse biting flies by breaking up polarized light.

UC Davis scientists explore the microbiome

Today’s White House announcement of the National Microbiome Initiative will bring new funding and attention to better understand the billions of microbes that swarm around in and around us and probably play an important role in our health, food and environment. At UC Davis, many scientists are already exploring this hidden world. Here are a few of them.

Jonathan Eisen is one of the pioneers of studying microbe communities through genetic sequencing. His lab is involved in understanding the complete “Tree of Life,” and projects on microbial communities associated with buildings, as well as communities on different plants and animals, including people, dogs and cats. A prolific blogger, Eisen regularly calls out examples of excessive microbiome hype.

How antibiotics open door to “bad” gut bacteria: more oxygen

By Carole Gan

Antibiotics are essential for fighting bacterial infection, but they can also make the body more prone to infection and diarrhea. Exactly how do antibiotics foster growth of disease-causing microbes – and how can resident “good” microbes in the gut protect against pathogens, such as Salmonella?

Now research led by Andreas Bäumler, professor of medical immunology and microbiology at UC Davis Health System, has identified the chain of events that occur within the gut lumen of mice after antibiotic treatment that allow “bad” bugs to flourish.

Microbe studies zoom in on effects of HIV in the gut

By Pat Bailey

The curtain cloaking how AIDS and HIV (human immunodeficiency virus) impact the human digestive and immune systems has been drawn back a bit further, thanks to a team of researchers from UC Davis’ departments of Food Science and Technology and Medical Microbiology and Immunology.

The small intestine­ is extremely difficult to study because of its location in the body but plays a critical role in human health. Its inner lining offers both a portal for absorbing nutrients and a barrier against toxins or invasive microbes.

West Coast Scientists Recommend Immediate Action Plan to Combat Ocean Acidification

By Kat Kerlin

Global carbon dioxide emissions are triggering permanent changes to ocean chemistry along the West Coast. Failure to act on this fundamental change in seawater chemistry, known as ocean acidification, is expected to have devastating ecological consequences for the West Coast in the decades to come, warns a multistate panel of scientists, including two from UC Davis Bodega Marine Laboratory.

Their report, issued this week, urges immediate action and outlines a regional strategy to combat the alarming global changes underway. Inaction now will reduce options and impose higher costs later, the report said.

Discovery links Brucella infection, inflammation, chronic diseases

By Carole Gan

Researchers at UC Davis have discovered an unexpected link between how the immune system sounds an alarm when its cells are taken over by pathogens during an infection and how an inflammatory response is triggered.

The finding of this novel link, published in the journal Nature on March 23, is important because it helps researchers understand how a cell senses bacterial or viral infection, and how these pathways are linked to inflammatory diseases, such as inflammatory bowel disease, diabetes and atherosclerosis.

Tide pools at the front line of ocean acidification

By Becky Oskin

Beloved by beach goers, tide pools are also important ecological zones that provide shelter and food for many plants and animals.

Marine life living in tide pools are vulnerable to rising acid levels in seawater, according to new research from UC Davis, the Carnegie Institution for Science and UC Santa Cruz published March 18 in the journal Scientific Reports.

Not so sweet: Why Pollinators Forage on Toxic or Bitter Nectar

Audio: Listen to this story on our podcast, Three Minute Egghead. 

By Kathy Keatley Garvey

Nectar doesn’t always taste so sweet, but honeybees and other pollinators still feed on it. Now UC Davis community ecologist Rachel Vannette has discovered why pollinators continue to forage on “toxic” or bitter-tasting nectar, despite what should be a deterrent.

In newly published research in the journal Ecology, Vannette notes that floral nectar is produced by many plants to reward pollinators, but this sugary secretion often contains chemical compounds that are bitter tasting or toxic, which should deter pollinators. Plants including citrus, tobacco (Nicotiana), milkweed (Asclepias), turtlehead (Chelone), Catalpa, and others produce nectar containing bioactive or toxic compounds.

UC Davis entomologists on the trail of virus-carrying mosquito

Aedes aegypti, a daytime-biting mosquito that predominantly feeds on humans, has spread to at least seven counties since June 2013, according to UC Davis medical entomologist Anthony Cornel of the UC Kearney Agricultural Research and Extension Center, Parlier, and the UC Davis Department of Entomology and Nematology.

Aedes aegypti carries yellow fever, Zika and other viruses. (CDC photo)

Aedes aegypti carries yellow fever, Zika and other viruses. (CDC photo)

“It’s an issue of great concern, especially as current control methods do not appear to be working well,” said Cornel, who does research on the mosquito in Clovis, Fresno County, where it was discovered in June 2013. Simultaneously, the insect was found in the cities of Madera and San Mateo.

Hepatitis virus-like particles as potential cancer treatment

UC Davis researchers have developed a way to use the empty shell of a Hepatitis E virus to carry vaccines or drugs into the body. The technique has been tested in rodents as a way to target breast cancer, and is available for commercial licensing through UC Davis Office of Research.

Hepatitis E virus is feco-orally transmitted, so it can survive passing through the digestive system, said Marie Stark, a graduate student working with Professor Holland Cheng in the UC Davis Department of Molecular and Cell Biology.