Fourier transform infrared (FTIR) spectroscopy for monitoring airborne gases and vapors of industrial hygiene concern.

There are few available analytical methods with which an industrial hygienist can perform near real-time identification and quantitation of gases and vapors in the workplace. At present, the instruments that come the closest to fulfilling this need are based on either Fourier transform infrared (FTIR) spectroscopy or mass spectroscopy (MS). In order to investigate the applicability of FTIR to the qualitative and quantitative analysis of gas and vapor emissions in the workplace, an investigation was carried out to choose optimal conditions that could maximize the signal from individual target analytes and minimize the potential for interference. In all cases, the limit of detection (LOD) of individual air contaminants was below the threshold limit value (TLV).

New recombinant HLA-B alleles in a tribe of South American Amerindians indicate rapid evolution of MHC class I loci.

Evidence suggests that the New World was colonized only 11,000-40,000 years ago by Palaeo-Indians. The descendants of these Palaeo-Indians therefore provide a unique opportunity to study the effects of selection on major histocompatibility complex class I genes over a short period. Here we analyse the class I alleles of the Waorani of South America and the Zuni of North America. Four of the Waorani HLA-B alleles were new functional variants which could be accounted for by intralocus recombination. In contrast, all of the Zuni HLA-A and -B molecules were present in caucasians and orientals. This suggests that the new Waorani HLA-B variants arose in South America. The description of four new HLA-B alleles in the Waorani and another five new HLA-B alleles from two other tribes of South American Amerindians indicates that the HLA-B locus can evolve rapidly in isolated populations. These studies underline the importance of gathering genetic data on endangered native human populations.