Eyjafjallajokull volcano ash causes more airline uncertainty

A new cloud of ash from the Eyjafjallajokull volcano in Iceland is continuing to add air traffic issues to parts of Europe, particularly to the United Kingdom.

The British National Air Traffic (NATS) and European officials have opened European airspace above 20,000 feet. Eruptions from the volcano have pushed ash over 10,000 feet, pushing some toward Britain.

The lack of visibility has caused flights to be canceled, most recently those to England, Wales and Scotland although they may be lifted later this week. Hundreds of thousands of passengers are stranded throughout the world due to the weeklong halt in flights.

(Source: nytimes.com)

Diet linked to lower Alzheimer’s risk later in life

    Maybe the age old adage about eating your vegetables has some truth after all.

    A diet rich in fish, poultry, fruits, nuts, dark leafy greens and certain vegetables has been shown to lower the risk for Alzheimer’s disease in older adults, a new study says.

     Older people who ate a diet with these foods showed a one-third lower risk over four years than people who ate diets rich in high-fat dairy products, butter, red meat and organ meat.

    The foods associated with the lower risk showed a lower amount of saturated fat and high amounts of folate, vitamin E and fatty acids.

     Published in Archives of Neurology, the study does not demonstrate a cause and effect relationship between diet and the chance of developing this disease, said Dr. Nikolaos Scarmeas, the paper’s senior author and assistant professor of neurology at Columbia University.

(Source: nytimes.com)

Better tests needed for cancer treatment drugs

    Certain cancer drugs may be only as good as the tests to find the cancer.

    Tumors developed from cancer tend to have extra copies of a certain protein, HER2. If the tumor does, a drug called Herceptin can block the protein in order to halt the tumor’s growth.

However, most tests to determine if this certain protein exists or not are surprisingly unreliable.

        To deal with this problem, cancer specialists on Monday announced new testing guidelines for certain protein targets, in order to help resolve this problem.

(Source: nytimes.com)

-Complied by NICK MARKWITH and ANGELA RUGGIERO

UC Davis researchers have affirmed an essential hypothesis in a 26-year-old DNA repair model – new evidence paving the way for further study into the molecular mechanisms that can affect cancer predisposition and developmental defects.

Before this work, the 1983 double-strand-break repair model’s key hypothesis had not been physically demonstrated in cells, said Wolf-Dietrich Heyer, professor of microbiology.

“This research is a really big step,” Heyer said.

Intermediate DNA structures called double-Holliday junctions are formed in vivo when the ends of a broken chromosome – a single piece of coiled DNA and protein found in cells – exchange strands with a second chromosome, according to a paper by department of microbiology research scientist Malgosia Bzymek. The paper is published in the Apr. 8 issue in the journal Nature.

“In this repair process called homologous recombination, the second chromosome acts as a template from which the broken chromosome can copy any missing or damaged DNA sequences,” said Neil Hunter, associate professor of microbiology and senior author on the paper, in an e-mail interview.

The work also confirmed that double-Holliday junctions appear in both the cell divisions of meiosis and mitosis, an occurrence previously surmised by researchers, but scientifically undetermined, Heyer said.

Throughout meiosis, or sexual reproduction, cells divide twice to produce sperm and egg cells.

“Crossovers are at the heart of this process; without the connections they provide, mom and dad chromosomes are often pulled in the same direction, and the resulting sperm or eggs have odd numbers of chromosomes,” Hunter said in a statement.

Throughout mitosis – the cell division process in which the body divides its non-sexual cells – a cell identically splits into two. But before the cell can divide, its chromosomes must be entirely copied. And homologous recombination helps fix breaks that arise during that DNA replication, according to a UC Davis press release.

“Homologous recombination is an essential repair process that helps fix problems that frequently occur as cells replicate their chromosomes,” Hunter said. “But homologous recombination is something of a double-edged sword because aberrations in the process cause chromosomal changes that can lead to cancer.”

Double-Holliday junctions can also resolve into crossovers – entire chromosome arms are exchanged at the site of repair.

“Crossovers can cause genetic changes that are tumorigenic,” Hunter said. “We also discovered that double-Holliday junctions represent a minor pathway of break repair, i.e. it appears that the cell actively prevents formation of double-Holliday junctions in order to limit crossovers and their associated problems.”

In the lab, the scientists devised an experiment to watch the repair happen at the molecular level. They observed the molecules breaking, interacting with the template chromosome, forming double-Holliday junctions and ultimately being restored.

Although the idea behind the research was not new, in many ways it represents a beginning, Hunter said.

“We’re especially interested to know how the formation of double-Holliday junctions is regulated.”

Heyer agrees.

“This has really profound pragmatic value for future cancer research,” he said.

Co-authors of the study were Nathaniel Thayer, then a UC Davis undergraduate and now graduate student at the University of Washington; Steven Oh, then a UC Davis graduate student and now a postdoctoral fellow at UCSF; and Nancy Kleckner of Harvard University. The work was supported by the National Institutes of Health and the Howard Hughes Medical Institute, said a UC Davis press release.

DAVID LEVINE can be reached at features@theaggie.org XXX

Researchers at UC Davis are developing new ways to aid those that are disabled. New studies are bringing forth revelations that could potentially make transportation and social independence much easier for both disabled children and adults.

These studies could prove vital in convenience, reliability and affordability for the disabled. If successfully implemented, researchers Sanjay Joshi and Anthony Wexler feel that it could drastically help the severely disabled – generally quadriplegics – operate wheelchairs, be more independent and allow for them to be more comfortable with their required machinery.

All this is being made possible through the development of an interface that utilizes electronic impulses to perform a desired action.

Joshi, associate professor of mechanical and aerospace engineering, started his research on this interface in 2005. Joshi set out with the goal of helping the disabled, especially children, better interact with society.

“Children and disabled people need to be able to interact,” Joshi said.

His research aimed at facilitating things for the disabled is new, but has not failed in garnering attention. Joshi is the latest recipient of The Hartwell Foundation’s grant for biomedical research – a grant which will allocate him $300,000 over the next three years. He said that though the research is just beginning to transform into literature, it has drawn much interest in conference presentations.

Joshi’s research aims to use an interface that targets the electronic impulses of facial muscles to help the disabled.

“Our approach is a new approach,” he said.

It is an approach that may eliminate some of the current limitations the disabled have by giving them further use of their head, tongue and chin.

Joshi points out that though current technologies are wonderful in helping the disabled, some can be limiting and uncomfortable. His interface is aiming to provide something that is as convenient and helpful as possible.

“Our interface can control things as unobtrusively as possible,” he said.

Joshi said how they are “hoping to add one more option” to the current technologies. He believes that this interface could potentially eliminate the current need for constant expensive upgrades to mechanical hardware.

The interface would rather be more reliant upon software upgrades, allowing the cost of the interface to be much lower, and thus more readily available to all disabled people in need of a machine.

“We’ll hopefully make it less expensive,” Joshi said.

The interface he is currently attempting to develop can be beneficial to many, but its impact will be mostly for children.

One of Joshi’s goals is to develop an interface that can adapt to children’s growth. This goal, while not yet achieved, is of great importance to Joshi; it is something that he admits the grant will greatly help with.

Anthony Wexler, professor of mechanical and aerospace engineering, has been helping Joshi with his research for five years, and believes their research to be something “very exciting.”

Wexler said the relatively simple motion of wiggling one’s ears could be enough for a disabled person to be able to control a wheelchair, or operate a computer.

Wexler said this uncommonly utilized muscle – that is not enervated to the spinal cord – can be ideal for the operating of something like a wheelchair. This muscle is ideal since it is not located at the front of the face, thus making the positioning of any robotics more comfortable and less obtrusive.

He said that children are more adept to learning how to control these electronic impulses as a result of it being easier for them to learn motor skills, than for adults. Wexler suggests that children are the main target due to their higher potential for benefit.

“It can help and benefit children longer,” he said.

Joshi and Wexler both regarded the potential impact as inspiration, believing that making the lives of disabled people better a motivation.

ERIC C. LIPSKY can be reached at features@theaggie.org 

Rebecca Skloot, journalist and author, will be speaking and signing copies of her new book, “The Immortal Life of Henrietta Lacks” on Friday at 4 p.m.

Held in the Activities and Recreation Center Ballroom, her bestselling book discusses the life of Henrietta Lacks, a Southern tobacco farmer who died more than 50 years ago, and how cells taken from her body proved to be the first human cells grown in a culture to be “immortal.”

These cells, called HeLa cells, became one of the most important tools in medicine and proved vital for developing the polio vaccine, uncovering the secrets of cancer and other medical breakthroughs.

However, Lacks’ family did not become aware of her “immortal” cells until 20 years after her death. They saw no profits from the medical advances and raised ethical issues about research on human biological materials.

Sponsored by the UC Davis Genome Center, the Science and Technology Studies Program, the University Writing Program and the Davis Humanities Institute, Skloot’s talk and book signing are free to the public.

-Text by NICK MARKWITH

(Source: UC Davis News Service)

You know that city-mouse/country-mouse story? Well, I feel like country-mouse right now. I’ve been interning this quarter in Washington, D.C. – a bustling city 2,388 miles from dear old Davis.

Traveling across this city has made me realize that I take a huge part of modern life for granted. There’s a great invention that makes it possible for me to travel underground on the subway and take an elevator 20 floors above street-level.

This technology is concrete. It’s the gray, coarse, wonderful material we build our lives on.

Think about this: Until 1309, the tallest freestanding structure on Earth was the Great Pyramid of Giza in Egypt. It was 481 feet tall. Today, the tallest building in the world is Burj Khalifa, a skyscraper in Dubai. It’s 2,717 feet tall – more than half a mile. This ridiculous new height is made possible by reinforced concrete.

The Romans had an early version of concrete, but if you’d told the ancients what concrete does for us today, it would have sounded like fantasy. Until 1994, the English Channel could only be crossed by boat or plane. Now, we can take a train underneath the 23.5 miles of ocean between France and the UK. Thank you, concrete.

“It’s the most widely used material in the world,” said Dr. John Bolander, associate professor of structural engineering and mechanics at UC Davis.

Bolander shared with me the recipe for concrete. The basic ingredients are water, cement and aggregates. Aggregates are little pieces of rock and sand. The cement is usually a kind called Portland cement, which is mainly crushed silica and limestone.

“Portland cement is the glue that binds everything together,” Bolander said.

These concrete ingredients can be found around the world, so once engineers perfected steel, concrete buildings reinforced with steel rebar sprang up everywhere. Concrete is stronger than wood, lighter than brick and more portable and shapeable than stone.

From my science-nerd perspective, the behavior of concrete is fascinating. Unlike glue, concrete doesn’t harden through a drying process. Concrete “cures,” which means the water reacts with chemicals in cement to produce crucial binding agents that make concrete strong. The chemical reaction causes concrete to heat up (an exothermic reaction), and it’s important to keep the concrete wet during this process.

Fun fact: When they built the Hoover Dam in the 1930s, engineers realized that heat from the chemical reaction in the concrete would take 125 years to dissipate naturally. The solution was to embed coils of steel pipe in the concrete slabs so cold river water could run through and cool it down.

Sadly, this fabulous technology has a drawback – concrete is environmentally unfriendly.

            To make Portland cement, you have to heat up the silica and limestone to 1,400 degrees Celsius. Portland cement production accounts for 5 to 10 percent of our CO2 production, Bolander explained. That’s a lot of energy. Plus, huge concrete structures can screw up natural ecosystems and agriculture by diverting rainwater when it falls.

Bolander was excited to tell me how material scientists are turning concrete green. One advance has been the invention of porous concrete, a material that allows rain to soak through to the soil below. With this technology comes the challenge of making concrete freeways strong enough for cars, but porous enough for water. New-fangled concrete could also be good for the atmosphere.

“They’re designing concrete now to actually remove CO2 from the atmosphere,” Bolander said.

Bolander said material scientists and engineers are looking to fly ash, a waste product of coal combustion, as an alternative to Portland cement. Fly ash is already mucking up the environment, so we should put it to good use.

When I walk up to my office in D.C., the sturdy concrete building feels as permanent as the pyramids. Yet the pyramids are changing, eroding and shrinking over time. Concrete changes, too. Newly poured concrete actually gets stronger after it has “cured.”

“It’s a chemical process that goes on for years,” Bolander said. “It’s alive.” 

MADELINE MCCURRY-SCHMIDT doesn’t usually write about engineering, so this column was a challenge. She dedicates this endnote to the inventor of the Cheez-It omelet. E-mail her column ideas at memschmidt@ucdavis.edu.