A variable tandem repeat locus mapped to chromosome band 10q26 is amplified and rearranged in leukocyte DNAs of two cancer patients.

A highly polymorphic locus associated with the variable tandem repetition of a 35 bp consensus sequence was mapped to chromosome 10, band q26. Examination of leukocyte DNA from a cancer patient revealed the twenty-fold amplification of one allelic fragment of this locus, while the other allelic fragment demonstrated a normal copy number. In another patient, Southern blotting of leukocyte DNA detected the deletion of the 3'-flanking region from one tandem repeat allele. These results indicate that variable tandem repeats may mark highly unstable regions of DNA in the human genome which can be altered by changes more extensive than simple tandem repeat variation

Source apportionment of particulate matter in a large city of southeastern Po Valley (Bologna, Italy)

This study reports the results of an experimental research project carried out in Bologna, a midsize town in central Po valley, with the aim at characterizing local aerosol chemistry and tracking the main source emissions of airborne particulate matter. Chemical speciation based upon ions, trace elements, and carbonaceous matter is discussed on the basis of seasonal variation and enrichment factors. For the first time, source apportionment was achieved at this location using two widely used receptor models (principal component analysis/multi-linear regression analysis (PCA/MLRA) and positive matrix factorization (PMF)). Four main aerosol sources were identified by PCA/MLRA and interpreted as: resuspended particulate and a pseudo-marine factor (winter street management), both related to the coarse fraction, plus mixed combustions and secondary aerosol largely associated to traffic and long-lived species typical of the fine fraction. The PMF model resolved six main aerosol sources, interpreted as: mineral dust, road dust, traffic, secondary aerosol, biomass burning and again a pseudo-marine factor. Source apportionment results from both models are in good agreement providing a 30 and a 33 % by weight respectively for PCA-MLRA and PMF for the coarse fraction and 70 % (PCA-MLRA) and 67 % (PMF) for the fine fraction. The episodic influence of Saharan dust transport on PM10 exceedances in Bologna was identified and discussed in term of meteorological framework, composition, and quantitative contribution