Joung-Mo Kang | PubMed Health

PubMed2004

Autoregressive modeling of analytical sensor data can yield classifiers in the predictor coefficient parameter space.

SUMMARY: The analysis of chromatographic data resulting from complex chemical mixtures is challenging. Components may co-elute, causing their signals to overlap. An algorithm that will increase the signal-to-noise ratio so compounds present in low abundance can be better distinguished from noise is useful in this type of analysis. The autoregressive (AR) filter offers the advantage of smoothing chromatograms to increase this ratio, while also offering data compression and increased resolution. Furthermore, this filter can be useful for classification, as the roots of the predictor coefficient vectors represent features present in the data and can therefore be used for pattern recognition. In this paper, we present a novel method for applying AR filtering to chromatogram data. We show that the AR filter outperforms the Savitzky-Golay filter for smoothing noise while retaining important information within chromatograms, and also that AR correlation coefficients have the potential to be used to classify chromatogram data into groups. CONTACT: cdavis@draper.com.

Algorithms↗

PubMed2004

Factors limiting the immunogenicity of HIV-1 gp120 envelope glycoproteins.

Efficient immune responses to HIV-1 gene products are essential elements to the development and design of an effective vaccine. Ideally, both humoral and cellular responses will be optimally elicited. It is therefore important to elucidate any factors that might limit the immunogenicity of HIV-1 proteins that are likely to be included in an effective vaccine. Since the HIV-1 exterior envelope glycoprotein gp120 is a major target for neutralizing antibodies, it is a virtual certainty that this gene product will be a component of any vaccine that seeks to elicit neutralizing antibody responses from the host humoral immune system. We report here the testing of several HIV-1 gp120 variants derived from a primary isolate that appears deficient in eliciting immune responses at both the level of CD4+ help and consequently in the generation of high-affinity IgG antibody responses in small animals. Factors limiting an effective immune response include (a) envelope glycoprotein strain variation decreasing functional T-cell help, (b) alteration of the glycosylation patterns of gp120 by expression in different cell types, and (c) the native structure of gp120 itself, which may limit the elicitation of effective T-cell help during natural infection or during parenteral immunization in adjuvant. Such limiting factors and others should be considered in the design and testing of gp120-based immunogens in small animals and possibly in primates as well.

AIDS Vaccines↗