RESUMO
'Biasong' (Citrus micrantha), native to the Southern Philippine Islands, is an important cultivated fruit tree but has no published plastome sequence. We assembled and characterized the C. micrantha chloroplast genome from accession in the germplasm collection of the Institute of Crop Science, University of the Philippines Los Baños. The complete chloroplast (cp) genome sequence is 159,928-bp long with 128 coding genes comprising 83 mRNA genes, 37 tRNA genes, and eight rRNA genes. Out of the mRNA genes, 45 genes code for photosynthesis, 30 genes code for self-replication, and five genes code for other functions. A phylogenetic analysis of the assembled genome, along with 24 Citrus species and three other Rutaceae species, identified Citrus aurantiifolia as its closest relative with available complete cpDNA sequence.
RESUMO
Coincidence counting techniques have been combined with time-of-flight mass spectrometry in the examination of surfaces for chemical microhomogeneity. A mathematical formalism was developed to describe the principles underlying this coincidence counting technique and was used to produce a quantitative method for handling the data obtained. This technique of testing for chemical homogeneity has been demonstrated with a sample that consists of a physical mixture of polystyrene and crystals of NaF which were tenths of micrometers in diameter. Ultimately this approach is expected to be useful for the routine testing of surfaces for chemical homogeneity at the level of tens of nanometers.
