Stories tagged Northwestern University

It's Friday, and y'all know what that means. Yup, time for a new Science Friday video.

Science Friday
Science FridayCourtesy Science Friday

This week,

"Many mammals have whiskers but not all whisk. Cats don't. Rats do. To whisk, rats use special muscles in their face to brush their whiskers against an object. From the bending bristles, rats seem to be able to decode an object's shape and texture and Mitra Hartmann, engineer at Northwestern University, wants to understand how. This week, Hartmann and colleagues published a 3D whisker model, which she says will help quantify what information the brain receives from a whisk."

May
01
2009

A research group led by Dirk Brockmann at Northwestern University has created a computer model that predicts the spread of the 2009 H1N1 influenza virus in the US. (It uses a complex set of mathematical equations to describe the movement of people and virus.)

How can you track and predict the movement of something so small?: Follow the money, of course! (This is a colorized negative stained transmission electron micrograph (TEM) showing some of the ultrastructural morphology of the A/CA/4/09 swine flu virus. Got that? Good.
How can you track and predict the movement of something so small?: Follow the money, of course! (This is a colorized negative stained transmission electron micrograph (TEM) showing some of the ultrastructural morphology of the A/CA/4/09 swine flu virus. Got that? Good.Courtesy CDC/C.S. Goldsmith and A. Balish

(Brockmann was a guest on Minnesota Public Radio's Midmorning show today, and you can listen to it online.)

The good news is that, based on what we know now, and assuming that no one takes any preventive measures, we could expect to see some 1,700 cases of swine flu in the next four weeks. Because of the preventive measures being taken wherever a suspected case of H1N1 flu has popped up, we should actually see fewer cases. (You can see Brockmann's models here.) That's lousy if you're one of the folks who picks up the virus, but not a devastating number of cases. Of course, this is a rapidly developing, fluid situation, and things may change. Still, tools like Brockmann's model help to ensure that emergency supplies and other resources get to the places likely to need them most before they're needed.

Professor's Computer Simulations Show Worst-Case Swine Flu Scenario from Northwestern News on Vimeo.

Don't have faith in computer models? Well, a second research group at Indiana University is using another model, with different equations, and getting very similar results. That's a pretty good indication that the predictions are reliable.

You might remember Brockmann from a 2006 study that used data from WheresGeorge.com, a site that allows users to enter the serial numbers from their dollar bills in order to see where they go, to predict the probability of a given bill remaining within a 10km radius over time. That gave him a very good picture of human mobility, reflecting daily commuting traffic, intermediate traffic, and long-distance air travel, all of which help to model how a disease could spread.

Feb
05
2008

Nano (not!): Built for the 1958 Brussels World's Fair, this model of a body-centred cubic crystal is similar to the nano crystal created with DNA except it is magnified 165 billion times.
Nano (not!): Built for the 1958 Brussels World's Fair, this model of a body-centred cubic crystal is similar to the nano crystal created with DNA except it is magnified 165 billion times.Courtesy John Kerno

First step toward three-dimensional catalytic, magnetic, and/or optical nanomaterials

Assembling structures that are 1000 times smaller than a human hair is difficult. One technique that works is known as "self assembly". A random mixture of microscopic parts can be coaxed into assembling spontaneously into a desired structure by attaching appropriate segments of DNA to various parts. Complementary DNA strands want to "pair up". This is how nano structures are assembled in living organisms.

"researchers at the U.S. Department of Energy's Brookhaven National Laboratory have for the first time used DNA to guide the creation of three-dimensional, ordered, crystalline structures of nanoparticles.

Nanomaterials: Golden handshake

The team from Brookhaven and another group from Northwestern University in Evanston, US, both started with tiny spheres of gold around 10 nanometres across, and attached short strands of DNA. By varying the length of the DNA strands, their flexibility,and the types of sticky ends, they are working toward reliably binding them together in particular ways. This is the first step toward building three-dimensional catalytic, magnetic, and/or optical nanomaterials.

Sources:

Oct
02
2007

Alzheimer's disease, often called "old timers disease" effects about 1 in 5 people over age 80. Called dementia, the symptoms include problems with memory, thinking, behavior, and emotion.

Alzheimer's similar to diabetes

Researchers at Northwestern University think that the mechanism of Alzheimer's involves insulin receptors in brain cells. In the brain, insulin and insulin receptors are vital to learning and memory.

A toxic protein found in the brains of individuals with Alzheimer's removes insulin receptors from nerve cells, rendering those neurons insulin resistant.
The protein, known to attack memory-forming synapses, is called an ADDL for "amyloid ß-derived diffusible ligand." Science Daily

William L. Klein, professor of neurobiology and physiology in the Weinberg College of Arts and Sciences, said he believes the findings are a major factor in the memory deficiencies caused by ADDLs in Alzheimer's brains and reveals a fundamental new connection between diabetes and Alzheimer's disease. This offers hope for therapeutics. Finding ways to make those insulin receptors themselves resistant to the impact of ADDLs. might not be so difficult.

Early detection of Alzheimer's Disease

Klein not only helped identify the bio-marker, ADDL, but also helped develop a technique to detect it in patients with early stage Alzheimer's using bio-bar-code amplification technology.

To detect ADDLs, a magnetic microparticle and a gold nanoparticle are each outfitted with an antibody specific to the ADDL antigen. When in solution, the antibodies “recognize” and bind to the ADDL, sandwiching the protein between the two particles. Fienberg School of Medicine

After the “particle-ADDL-particle” sandwich is removed magnetically from solution, the bar-code DNA is removed from the sandwich and read using standard DNA detection methodologies. The researchers next would like to develop the technology so that the test could be done using a blood or urine sample instead of cerebrospinal fluid, which is more difficult to obtain.