Comparison of the binding stoichiometries of positively charged DNA-binding drugs using positive and negative ion electrospray ionization mass spectrometry

Positive and negative ion electrospray ionization (ESI) mass spectra of complexes of positively charged small molecules (distamycin, Hoechst 33258, [Ru(phen)2dpq]Cl2 and [Ru(phen)2dpqC]Cl2) have been compared. [Ru(phen)2dpq]Cl2 and [Ru(phen)2dpqC]Cl2 bind to DNA by intercalation. Negative ion ESI mass spectra of mixtures of [Ru(phen)2dpq]Cl2 or [Ru(phen)2dpqC]Cl2 with DNA showed ions from DNA-ligand complexes consistent with solution studies. In contrast, only ions from freeDNAwere present in positive ion ESI mass spectra of mixtures of [Ru(phen)2dpq]Cl2 or [Ru(phen)2dpqC]Cl2 with DNA, highlighting the need for obtaining ESI mass spectra of non-covalent complexes under a range of experimental conditions. Negative ion spectra of mixtures of the minor groove binder Hoechst 33258 with DNA containing a known minor groove binding sequence were dominated by ions from a 1:1 complex. In contrast, in positive ion spectra there were also ions present from a 2:1 (Hoechst 33258: DNA) complex, suggesting an alternative binding mode was possible either in solution or in the gas phase. When Hoechst 33258 was mixed with a DNA sequence lacking a high affinity minor groove binding site, the negative ion ESI mass spectra showed that 1:1 and 2:1 complexes were formed, consistent with existence of binding modes other than minor groove binding. The data presented suggest that comparison of positive and negative ion ESI-MS spectra might provide an insight into various binding modes in both solution and the gas phase.

Population structure of Bactrocera dorsalis s.s., B. papayae and B. philippinensis (Diptera: Tephritidae) in southeast Asia: evidence for a single species hypothesis using mitochondrial DNA and wingshape data

Background Bactrocera dorsalis s.s. is a pestiferous tephritid fruit fly distributed from Pakistan to the Pacific, with the Thai/Malay peninsula its southern limit. Sister pest taxa, B. papayae and B. philippinensis, occur in the southeast Asian archipelago and the Philippines, respectively. The relationship among these species is unclear due to their high molecular and morphological similarity. This study analysed population structure of these three species within a southeast Asian biogeographical context to assess potential dispersal patterns and the validity of their current taxonomic status. Results Geometric morphometric results generated from 15 landmarks for wings of 169 flies revealed significant differences in wing shape between almost all sites following canonical variate analysis. For the combined data set there was a greater isolation-by-distance (IBD) effect under a ‘non-Euclidean’ scenario which used geographical distances within a biogeographical ‘Sundaland context’ (r2 = 0.772, P < 0.0001) as compared to a ‘Euclidean’ scenario for which direct geographic distances between sample sites was used (r2 = 0.217, P < 0.01). COI sequence data were obtained for 156 individuals and yielded 83 unique haplotypes with no correlation to current taxonomic designations via a minimum spanning network. BEAST analysis provided a root age and location of 540kya in northern Thailand, with migration of B. dorsalis s.l. into Malaysia 470kya and Sumatra 270kya. Two migration events into the Philippines are inferred. Sequence data revealed a weak but significant IBD effect under the ‘non-Euclidean’ scenario (r2 = 0.110, P < 0.05), with no historical migration evident between Taiwan and the Philippines. Results are consistent with those expected at the intra-specific level. Conclusions Bactrocera dorsalis s.s., B. papayae and B. philippinensis likely represent one species structured around the South China Sea, having migrated from northern Thailand into the southeast Asian archipelago and across into the Philippines. No migration is apparent between the Philippines and Taiwan. This information has implications for quarantine, trade and pest management.

Content sharing on public screens: experiences through iterating social and spatial contexts

This paper describes the design and study of public urban screen applications aiming to facilitate urban dwellers to control content shown on public urban screens. Two types of content sharing are presented: aggregating existing social media content about particular locations for sharing, and sharing online videos with collocated people at a public urban screen. The paper describes an exploratory study, an observational study, as well as an interpretational study in regards to application usage and user experience. Sharing content on public urban screens can pique the curiosity of users towards collocated people and the application itself resulting in raised awareness of collocated people.

Convergence and Australian content : the importance of access

In the light of new and complex challenges to media policy and regulation, the Austrlaian government commissioned the Convergence Review in late 2010 to assess the continuing applicability and utility of the principles and objectives that have shaped the policy framework to this point. It proposed a range of options for policy change and identified three enduring priorities for continued media regulation: media ownership and control; content standards; and Australian content production and distribution. The purpose of this article is to highlight an area where we feel there are opportunities for further discussion and research: the question of how the accessibility and visibility of Australian and local content may be assured in the future media policy framework via a combination of regulation and incentives to encourage innovation in content distribution.

The Convergence Review and the future of Australian content regulation

This article examines the place of Australian and local content regulation in the new media policy framework proposed by the Convergence Review. It outlines the history of Australian content regulation and the existing policy framework, before going on to detail some of the debates around Australian content during the Review. The final section analyses the relevant recommendations in the Convergence Review Final Report, and highlights some issues and problems that may arise in the new framework.

The pedagogical, linguistic and content features of popular English language learning websites in China : a framework for analysis and design

As increasing numbers of Chinese language learners choose to learn English online (CNNIC, 2012), there is a need to investigate popular websites and their language learning designs. This paper reports on the first stage of a study that analysed the pedagogical, linguistic and content features of 25 Chinese English Language Learning (ELL) websites ranked according to their value and importance to users. The website ranking was undertaken using a system known as PageRank. The aim of the study was to identify the features characterising popular sites as opposed to those of less popular sites for the purpose of producing a framework for ELL website design in the Chinese context. The study found that a pedagogical focus with developmental instructional materials accommodating diverse proficiency levels was a major contributor to website popularity. Chinese language use for translations and teaching directives and intermediate level English for learning materials were also significant features. Content topics included Anglophone/Western and non-Anglophone/Eastern contexts. Overall, popular websites were distinguished by their mediation of access to and scaffolded support for ELL.

Australian lungfish (Neoceratodus forsteri: Dipnoi) have low genetic variation at allozyme and mitochondrial DNA loci : a conservation alert?

Genetic variation at allozyme and mitochondrial DNA loci was investigated in the Australian lungfish, Neoceratodus forsteri Krefft 1870. Tissue samples for genetic analysis were taken non-lethally from 278 individuals representing two spatially distinct endemic populations (Mary and Burnett rivers), as well as one population thought to be derived from an anthropogenic translocation in the 1890's (Brisbane river). Two of 24 allozyme loci resolved from muscle tissue were polymorphic. Mitochondrial DNA nucleotide sequence diversity estimated across 2,235 base pairs in each of 40 individuals ranged between 0.000423 and 0.001470 per river. Low genetic variation at allozyme and mitochondrial loci could be attributed to population bottlenecks, possibly induced by Pleistocene aridity. Limited genetic differentiation was detected among rivers using nuclear and mitochondrial markers suggesting that admixture may have occurred between the endemic Mary and Burnett populations during periods of low sea level when the drainages may have converged before reaching the ocean. Genetic data was consistent with the explanation that lungfish were introduced to the Brisbane river from the Mary river. Further research using more variable genetic loci is needed before the conservation status of populations can be determined, particularly as anthropogenic demands on lungfish habitat are increasing. In the interim we recommend a management strategy aimed at conserving existing genetic variation within and between rivers.

The influence of oxygenated organic aerosols (OOA) and its volatile organic content on the oxidative potential of diesel particulate mater

Airborne particulate matter pollution is of concern for a number of reasons and has been widely recognised as an important risk factor to human health. A number of toxicological and epidemiological studies reported negative health effects on both respiratory and cardiovascular system. Despite the availability of a huge body of research, the underlying toxicological mechanisms by which particles induce adverse health effects are not yet entirely understood. The production of reactive oxygen species (ROS) has been shown to induce oxidative stress, which is proposed as a mechanism for many of the adverse health outcomes associated with exposure to particulate matter (PM). Therefore, it is crucial to introduce a technique that will allow rapid and routine screenings of the oxidative potential of PM.

Media classification : Content regulation in an age of convergent media

This article outlines the key recommendations of the Australian Law Reform Commission’s review of the National Classification Scheme, as outlined in its report Classification – Content Regulation and Convergent Media (ALRC, 2012). It identifies key contextual factors that underpin the need for reform of media classification laws and policies, including the fragmentation of regulatory responsibilities and the convergence of media platforms, content and services, as well as discussing the ALRC’s approach to law reform.

Effects of lime content and amelioration period in double lime application on the strength of lime treated expansive sub-grade soils

The addition of lime into soils has been widely used to stabilize the expansive sub-grade soils when the road pavements are constructed on them. It is common practice to apply a half of the required lime amount and allow a certain time period for lime to react with soils (Amelioration period) before applying the rest of lime and compacting the sub-grade. The optimum amelioration period is essential to minimize the construction delay and to gain the higher strength. In this study, two different expansive soils procured from two different locations in the state of Queensland in Australia were first mixed with different lime contents. A soil mixed with a particular lime content was compacted at different amelioration periods (e.g.: 0, 6, 12, 18, 24 hrs) to obtain soil samples to measure the Unconfined Compressive Strength (UCS). The results suggested that for a given amelioration period, UCS increased with the increase in lime content. The optimum amelioration period could be within 14~17 hours for most of the lime contents in tested soils. This could suggest that the current 24-48 hour amelioration period specified by the Queensland Department of Transport and Main roads could be reduced.

Next-generation sequencing of cervical DNA detects human papillomavirus types not detected by commercial kits

Background Human papillomavirus (HPV) is the aetiological agent for cervical cancer and genital warts. Concurrent HPV and HIV infection in the South African population is high. HIV positive (+) women are often infected with multiple, rare and undetermined HPV types. Data on HPV incidence and genotype distribution are based on commercial HPV detection kits, but these kits may not detect all HPV types in HIV + women. The objectives of this study were to (i) identify the HPV types not detected by commercial genotyping kits present in a cervical specimen from an HIV positive South African woman using next generation sequencing, and (ii) determine if these types were prevalent in a cohort of HIV-infected South African women. Methods Total DNA was isolated from 109 cervical specimens from South African HIV + women. A specimen within this cohort representing a complex multiple HPV infection, with 12 HPV genotypes detected by the Roche Linear Array HPV genotyping (LA) kit, was selected for next generation sequencing analysis. All HPV types present in this cervical specimen were identified by Illumina sequencing of the extracted DNA following rolling circle amplification. The prevalence of the HPV types identified by sequencing, but not included in the Roche LA, was then determined in the 109 HIV positive South African women by type-specific PCR. Results Illumina sequencing identified a total of 16 HPV genotypes in the selected specimen, with four genotypes (HPV-30, 74, 86 and 90) not included in the commercial kit. The prevalence's of HPV-30, 74, 86 and 90 in 109 HIV positive South African women were found to be 14.6 %, 12.8 %, 4.6 % and 8.3 % respectively. Conclusions Our results indicate that there are HPV types, with substantial prevalence, in HIV positive women not being detected in molecular epidemiology studies using commercial kits. The significance of these types in relation to cervical disease remains to be investigated.