In biology, scientists typically conduct experiments first, and then develop mathematical or computer models afterward to show how the collected data fit with theory. In his work, Rob Phillips flips that practice on its head. The Caltech biophysicist tackles questions in cellular biology as a physicist would—by first formulating a model that can make predictions and then testing those predictions. Using this strategy, Phillips and his group have recently developed a mathematical model that accounts for the way genes compete with each other for the proteins that regulate their expression.
A paper describing the work appears in the current issue of the journal Cell. The lead authors on the paper are Robert Brewster and Franz Weinert, postdoctoral scholars in Phillips’s lab.
Posted February 28, 2014on:
UT Southwestern Medical Center researchers created new nerve cells in the brains and spinal cords of living mammals without the need for stem cell transplants to replenish lost cells.
Although the research indicates it may someday be possible to regenerate neurons from the body’s own cells to repair traumatic brain injury or spinal cord damage or to treat conditions such as Alzheimer’s disease, the researchers stressed that it is too soon to know whether the neurons created in these initial studies resulted in any functional improvements, a goal for future research.
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Operating on a child’s heart is a challenging procedure. Not only is the organ (presumably) defective, but it’s also small, complex, and delicate. So when Louisville, KY heart surgeon Erle Austin was preparing to operate on 14-month-old Roland Lian Cung Bawi’s heart, he first showed the scans of the muscle to two other surgeons, both of whom gave him “conflicting advice on how to proceed,” according to the Courier-Journal.
Then, Austin turned to the University of Louisville’s engineering school, which hooked him up with a MakerBot Replicator 2X. (From the video, it seems that the engineers had better luck with their 3D MakerBot printers than Ars ever did.) Using a computer model generated by the boy’s radiologist, the engineers fed the MakerBot with a new kind of flexible polymer “that’s similar in consistency to heart muscle,” Timothy Gornet, manager of the rapid prototyping center at U of L, told the Courier-Journal. They printed out three cross-sections of the heart, blown up to-scale, so that the surgeons could see the interior.
his 3D medical animation shows the function of white blood cells in normal immunity. It also portrays how the human immunodeficiency virus (HIV) affects the immune system and causes acquired immunodeficiency syndrome (AIDS). Common types of antiretroviral medications used to treat HIV and AIDS are also shown.
Engineers like to make things that work. And if one wants to make something work using nanoscale components—the size of proteins, antibodies, and viruses—mimicking the behavior of cells is a good place to start since cells carry an enormous amount of information in a very tiny packet. As Erik Winfree, professor of computer science, computation and neutral systems, and bioengineering, explains, “I tend to think of cells as really small robots. Biology has programmed natural cells, but now engineers are starting to think about how we can program artificial cells. We want to program something about a micron in size, finer than the dimension of a human hair, that can interact with its chemical environment and carry out the spectrum of tasks that biological things do, but according to our instructions.”
Getting tiny things to behave is, however, a daunting task. A central problem bioengineers face when working at this scale is that when biochemical circuits, such as the one Winfree has designed, are restricted to an extremely small volume, they may cease to function as expected, even though the circuit works well in a regular test tube. Smaller populations of molecules simply do not behave the same as larger populations of the same molecules, as a recent paper in Nature Chemistry demonstrates.
What does it take to regrow bone in mass quantities? Typical bone regeneration — wherein bone is taken from a patient’s hip and grafted onto damaged bone elsewhere in the body — is limited and can cause great pain just a few years after operation. In an informative talk, Molly Stevens introduces a new stem cell application that harnesses bone’s innate ability to regenerate and produces vast quantities of bone tissue painlessly.
For the first time ever, neuroscientists have completed a comprehensive roadmap of the top-trafficked communication highways in the human brain.
This white-matter map not only charts the geography of these neural highways – it also plots out which of them interact with the most other paths, which are most crucial for supporting key brain functions, and which ones leave the whole brain most vulnerable to long-term damage if they’re disrupted.