New research by scientists at The Scripps Research Institute (TSRI) and other institutions provides a close-up look at the cone-shaped shell that is the hallmark of human immunodeficiency virus (HIV). The genetic material within HIV is enclosed within a shell called the capsid, which is formed by a honeycomb arrangement of about 250 hexagonal protein building blocks. For HIV to infect human cells, the virus binds to cell surface receptors, and then the capsid is delivered into the cytoplasm of the cell.
In an online issue of the journal Cell researchers at TSRI, University of Virginia, and University of Utah describe the first high-resolution molecular structure of the hexagonal protein building block that makes up the HIV capsid. Knowing how it is held together may reveal possible ways to break it apart and block HIV infection.
Congenital limb defects
Congenital birth defects of the arms, legs, hands or feet result from improper development of limb bud tissues during embryogenesis: the point at which previously undifferentiated cells become the specific cell types that ultimately develop into body structures and organs. For decades, it was thought that retinoic acid (a derivative of vitamin A) controlled limb "patterning" that directs a thumb to develop differently from a little finger, for example.
Working with fish and mice models, Burnham Institute for Medical Research researchers report findings that correct longstanding misconceptions about limb development. Previously it was thought that retinoic acid controlled both forelimb and hindlimb budding as well as patterning at both sites. While the Burnham study confirmed retinoid A is necessary for forelimb budding, surprisingly, it found it was not required for hindlimb budding. Also, the study showed retinoic acid played no role in limb patterning.
The study provides new insights into congenital limb defects and is published online in the journal Current Biology.
Imaging concealed weapons
Electrical engineering students from UCSD have invented radio frequency integrated circuits (RFICs) that could lead to significantly less expensive imaging systems for identifying concealed weapons, for helping helicopters to land during dust storms, and for high-frequency data communications. RFIC is the technology responsible for the communications links in all wireless devices. The new UCSD circuit has the advantage of using standard silicon semiconductor technology which is less expensive than what is current in use in today's security imaging systems working in the same frequency range.
The research was presented at the 2009 IEEE Radio Frequency Integrated Circuits Symposium, where it won a best student paper award.