Macquarie University

About: Macquarie University is a education organization based out in Sydney, New South Wales, Australia. It is known for research contribution in the topics: Population & Laser. The organization has 14075 authors who have published 47673 publications receiving 1416184 citations. The organization is also known as: Macquarie uni.

Numerous transposed sequences of mitochondrial cytochrome oxidase I-II in aphids of the genus Sitobion (Hemiptera: Aphididae).

Abstract: Polymerase chain reaction (PCR) products corresponding to 803 bp of the cytochrome oxidase subunits I and II region of mitochondrial DNA (mtDNA COI-II) were deduced to consist of multiple haplotypes in three Sitobion species. We investigated the molecular basis of these observations. PCR products were cloned, and six clones from one individual per species were sequenced. In each individual, one sequence was found commonly, but also two or three divergent sequences were seen. The divergent sequences were shown to be nonmitochondrial by sequencing from purified mtDNA and Southern blotting experiments. All seven nonmitochondrial clones sequenced to completion were unique. Nonmitochondrial sequences have a high proportion of unique sites, and very few characters are shared between nonmitochondrial clones to the exclusion of mtDNA. From these data, we infer that fragments of mtDNA have been transposed separately (probably into aphid chromosomes), at a frequency only known to be equalled in humans. The transposition phenomenon appears to occur infrequently or not at all in closely related genera and other aphids investigated. Patterns of nucleotide substitution in mtDNA inferred over a parsimony tree are very different from those in transposed sequences. Compared with mtDNA, nonmitochondrial sequences have less codon position bias, more even exchanges between A, G, C and T, and a higher proportion of nonsynonymous replacements. Although these data are consistent with the transposed sequences being under less constraint than mtDNA, changes in the nonmitochondrial sequences are not random: there remains significant position bias, and probable excesses of synonymous replacements and of conservative inferred amino acid replacements. We conclude that a proportion of the inferred change in the nonmitochondrial sequences occurred before transposition. We believe that Sitobion aphids (and other species exhibiting mtDNA transposition) may be important for studying the molecular evolution of mtDNA and pseudogenes. However, our data highlight the need to establish the true evolutionary relationships between sequences in comparative investigations.

The Process of Customer Engagement: A Conceptual Framework

Abstract: Traditional measures of customer satisfaction have been criticized for failing to capture the depth of customer responses to service performance. This study seeks to redirect satisfaction research ...

Financial accounting: in communicating reality, we construct reality.

Abstract: At first I saw Don Juan simply as a rather peculiar man who knew a great deal…but the people…believed that he had some sort of “secret knowledge”, that he was a “brujo”. The Spanish word brujo means, in English…sorcerer. It connotes essentially a person who has extraordinary…powers. I had known Don Juan for a whole year before he took me into his confidence. One day he explained that he possessed a certain knowledge that he had learned from a teacher, a “benefactor” as he called him, who had directed him in a kind of apprenticeship. Don Juan had, in turn, chosen me to serve as his apprentice, but he warned me that I would have to make a very deep commitment and that the training was long and arduous… My field notes disclose the subjective version of what I perceived while undergoing the experience. That version is presented here… My field notes also reveal the content of Don Juan's system of beliefs. I have condensed long pages of questions and answers between Don Juan and myself in order to avoid reproducing the repetitiveness of conversation…(The Teachings of Don Juan: A Yaqui Way of Knowledge, Carlos Castaneda, 1970, pp. 14, 24, 25).

The genome of the sea urchin Strongylocentrotus purpuratus.

Abstract: We report the sequence and analysis of the 814-megabase genome of the sea urchin Strongylocentrotus purpuratus, a model for developmental and systems biology. The sequencing strategy combined whole-genome shotgun and bacterial artificial chromosome (BAC) sequences. This use of BAC clones, aided by a pooling strategy, overcame difficulties associated with high heterozygosity of the genome. The genome encodes about 23,300 genes, including many previously thought to be vertebrate innovations or known only outside the deuterostomes. This echinoderm genome provides an evolutionary outgroup for the chordates and yields insights into the evolution of deuterostomes.