About Egghead

Egghead is a blog about research by, with or related to UC Davis. Comments on posts are welcome, as are tips and suggestions for posts. General feedback may be sent to Andy Fell. This blog is created and maintained by UC Davis Strategic Communications, and mostly edited by Andy Fell.

Thermal Transistor Handles Heat at the Nanoscale

By Andrew Myers

You’ve felt the heat before — the smartphone that warms while running a navigation app or the laptop that gets too hot for your lap.

The heat produced by electronic devices does more than annoy users. Heat-induced voids and cracking can cause chips and circuits to fail.


Schematic of the experimental thermal transistor. A slice of molybdenum disulfide (MoS2) sits on a piece of silicon dioxide, bathed in a solution of lithium ions. (Sood et al, Nature Communications)

Visualizing “Unfurling” Microtubule Growth

Living cells depend absolutely on tubulin, a protein that forms hollow tube-like polymers, called microtubules, that form scaffolding for moving materials inside the cell. Tubulin-based microtubule scaffolding allows cells to move, keeps things in place or moves them around. When cells divide, microtubule fibers pull the chromosomes apart into new cells. Cells with defects in tubulin polymerization die.

Microtubule fibers are hollow rods made of much smaller tubulin subunits that spontaneously assemble at one end of the rod, but exactly how they do this inside the crowded environment of living cells has been a mystery. Now researchers at UC Davis have uncovered the mechanism that puts these blocks in place, illustrated in a new animation.

Measuring Wear in Bone Tools

A UC Davis anthropologist has been building a catalog of high-resolution 3D models of bone tools worn by working various materials, all in the name of archaeology.

UC Davis graduate student Naomi Martisius with a rib bone she has shaped as a leather-working tool. Bone tools like these are often found in archaeological sites with the tips broken off.

Humans have been using bone tools for about two million years, and by about 100 thousand years ago were processing bones to make tools for specific purposes, such as working animal skins into leather. Both the way tools are made, and the way they are used, leave tiny marks on the bones that could give information about how these tools were prepared and used.

The Whole Tooth: New Method to Find Biological Sex From a Single Tooth

A team led by UC Davis researchers have come up with a new way to estimate the biological sex of human skeletal remains based on protein traces from teeth.

Tooth of a European-American buried in San Francisco in the 1850s. A new technique developed at UC Davis allows archaeologists
to find a person’s biological sex based on a single tooth. (Jelmer Eerkens)

Estimating the sex of human remains is important for archaeologists who want to understand ancient societies and peoples. Researchers can measure features of bones that differ between males and females, usually the pelvis. But skeletons of children and adolescents don’t show these structural changes, and often sites may only yield a few pieces of bone.

Livestreaming From The Sea Floor

The Schmidt Ocean Institute R/V Falkor is exploring hydrothermal vents off the coast of Mexico. (Schmidt Ocean Institute)

Robert Zierenberg, professor emeritus of geology at UC Davis, is currently Chief Scientist on the R/V Falkor, on a cruise exploring hydrothermal vents off the time of Baja, Mexico. The Falkor, owned by the Schmidt Ocean Institute, is using remote operated vehicles to explore the newly discovered vents and live  streaming the dives online.

Information on the cruise can be found on the SOI web site and the scientists onboard are posting blogs in both English and Spanish about their research on the site.

Exploring the Role of Redox and Bioelectric Players in Tissue Regeneration

Regeneration of a lost limb is arguably one of the seven wonders of biology. While you can’t grow a new arm, a humble tadpole can grow a new tail in a week. Seeking a better understanding of limb regeneration, Min Zhao, professor of dermatology and ophthalmology at the University of California, Davis, and graduate student Fernando Ferreira (also at University of Minho, Portugal) are studying the relationship of redox players, like oxygen and hydrogen peroxide, with bioelectricity, including membrane potential and electric currents, to pinpoint how a tadpole can regrow an amputated tail.

Detecting E.coli Strains Using Molecular Electronics

New technology developed by Josh Hihath and colleagues at UC Davis uses atomically fine electrodes to suspend a DNA probe that binds target RNA. The device is able to detect as little as a one-base change in RNA, enough to detect toxic strains of E. coli.

By Aditi Risbud Bartl

Finding a fast and inexpensive way to detect specific strains of bacteria and viruses is critical to food safety, water quality, environmental protection and human health. However, current methods for detecting illness-causing strains of bacteria such as E. coli require either time-intensive biological cell cultures or DNA amplification approaches that rely on expensive laboratory equipment.

Diagnosing and Treating Personality Disorders Needs a Dynamic Approach

By Karen Nikos-Rose

Someone who is “neurotic” does not necessarily show anger or anxiety in a given situation, even though those are generally accepted traits of a person with that personality style.

New UC Davis research suggests that lumping those with personality disorders into a package of traits should be left behind for more dynamic analysis instead. Those who study and treat people with personality disorders need to more deeply look at personality dynamics and variation over time, not just box people into specific categories or traits.

UC Davis psychologist Chris Hopwood wants to take a more dynamic view of personality traits and disorders.

Grant to Improve Poultry Production Worldwide

USAID awards second phase of funding to Genomics to Improve Poultry Innovation Lab 

By Diane Nelson

Throughout Africa, chickens are vital to family nourishment, income and food security. But African poultry production is threatened by an extremely virulent Newcastle disease virus that can decimate entire flocks within days.

UC Davis Animal Science Professor Huaijun Zhou with white leghorn chickens at a UC Davis facility. Zhou uses genetic and genomic techniques to breed chickens that are more resistant to disease and heat stress for developing world farmers. (Gregory Urquiaga)

Study Explores How Fruit Flies Navigate Unstable Convective Air

By Greg Watry

Drosophila melanogaster

The fruit fly Drosophila melanogaster lives in deserts and also urban environments with many hot surfaces and resulting air currents. (Photo: Sanjay Acharya)

When insects migrate over vast distances, many take advantage of a natural phenomenon called thermal convection, which causes flow movement when air at different temperatures interact. Hitching a ride on invisible rollercoasters called convection cells, insects—like aphids and spiders—follow the flow of warm air upwards and cold air downwards.

“They are floating up to 3,000 feet,” said Victor Ortega-Jimenez, an assistant project scientist in the Combes Lab at UC Davis, of this movement. “All these clouds of insects are floating up there and moving in these convection cell patterns.”