Grounding the internet : categorising the geographies of locative media

Taxonometrical uncertainty is prevalent in the field of locative media, which has been variously referred to as “the geomobile web” (Crawford and Goggin, 2009), “the geoweb” (Lake et al., 2004), “Where 2.0” (O’Reilly, 2008:1), and “DigiPlace” (Zook and Graham, 2007). However, it is not only the rapid development of the technology, or the various academic disciplinary approaches to it, that have resulted in this uncertainty but also the deeply ideological debates and concerns about what locative media should and should not be. The intention of this article is to provide an overview of existing literature and research in this field in order to develop a synthetic overview of the various types of locative media, and the geographies arising from them. Not only will such taxonomy clarify communication about locative media, it will identify for developers, users, policy-makers and scholars the specific contours and affordances of the different types of locative media, as well as the issues associated with them.

Synthesizing and databasing fossil calibrations: divergence dating and beyond

Divergence dating studies, which combine temporal data from the fossil record with branch length data from molecular phylogenetic trees, represent a rapidly expanding approach to understanding the history of life. National Evolutionary Synthesis Center hosted the first Fossil Calibrations Working Group (3–6 March, 2011, Durham, NC, USA), bringing together palaeontologists, molecular evolutionists and bioinformatics experts to present perspectives from disciplines that generate, model and use fossil calibration data. Presentations and discussions focused on channels for interdisciplinary collaboration, best practices for justifying, reporting and using fossil calibrations and roadblocks to synthesis of palaeontological and molecular data. Bioinformatics solutions were proposed, with the primary objective being a new database for vetted fossil calibrations with linkages to existing resources, targeted for a 2012 launch.

Relaxed phylogenetics and dating with confidence

In phylogenetics, the unrooted model of phylogeny and the strict molecular clock model are two extremes of a continuum. Despite their dominance in phylogenetic inference, it is evident that both are biologically unrealistic and that the real evolutionary process lies between these two extremes. Fortunately, intermediate models employing relaxed molecular clocks have been described. These models open the gate to a new field of “relaxed phylogenetics.” Here we introduce a new approach to performing relaxed phylogenetic analysis. We describe how it can be used to estimate phylogenies and divergence times in the face of uncertainty in evolutionary rates and calibration times. Our approach also provides a means for measuring the clocklikeness of datasets and comparing this measure between different genes and phylogenies. We find no significant rate autocorrelation among branches in three large datasets, suggesting that autocorrelated models are not necessarily suitable for these data. In addition, we place these datasets on the continuum of clocklikeness between a strict molecular clock and the alternative unrooted extreme. Finally, we present analyses of 102 bacterial, 106 yeast, 61 plant, 99 metazoan, and 500 primate alignments. From these we conclude that our method is phylogenetically more accurate and precise than the traditional unrooted model while adding the ability to infer a timescale to evolution.

Dating of divergences within the Rattus genus phylogeny using whole mitochondrial genomes

The timing and order of divergences within the genus Rattus have, to date, been quite speculative. In order to address these important issues we sequenced six new whole mitochondrial genomes from wild-caught specimens from four species, Rattus exulans, Rattus praetor, Rattus rattus and Rattus tanezumi. The only rat whole mitochondrial genomes available previously were all from Rattus norvegicus specimens. Our phylogenetic and dating analyses place the deepest divergence within Rattus at ∼3.5 million years ago (Mya). This divergence separates the New Guinean endemic R. praetor lineage from the Asian lineages. Within the Asian/Island Southeast Asian clade R. norvegicus diverged earliest at ∼2.9 Mya. R. exulans and the ancestor of the sister species R. rattus and R. tanezumi subsequently diverged at ∼2.2 Mya, with R. rattus and R. tanezumi separating as recently as ∼0.4 Mya. Our results give both a better resolved species divergence order and diversification dates within Rattus than previous studies.

Branch-length estimation bias misleads molecular dating for a vertebrate mitochondrial phylogeny

Despite recent methodological advances in inferring the time-scale of biological evolution from molecular data, the fundamental question of whether our substitution models are sufficiently well specified to accurately estimate branch-lengths has received little attention. I examine this implicit assumption of all molecular dating methods, on a vertebrate mitochondrial protein-coding dataset. Comparison with analyses in which the data are RY-coded (AG → R; CT → Y) suggests that even rates-across-sites maximum likelihood greatly under-compensates for multiple substitutions among the standard (ACGT) NT-coded data, which has been subject to greater phylogenetic signal erosion. Accordingly, the fossil record indicates that branch-lengths inferred from the NT-coded data translate into divergence time overestimates when calibrated from deeper in the tree. Intriguingly, RY-coding led to the opposite result. The underlying NT and RY substitution model misspecifications likely relate respectively to “hidden” rate heterogeneity and changes in substitution processes across the tree, for which I provide simulated examples. Given the magnitude of the inferred molecular dating errors, branch-length estimation biases may partly explain current conflicts with some palaeontological dating estimates.

Life in the internet economy and the changing face of property use

Increased participation in the internet economy is actively encouraged and supported by all levels of government. Research to date clearly shows the positive impacts that increased internet access can bring, particularly for rural Australia. Meanwhile, for the most part, identification of any negative impacts of increased broadband access on existing and potential property uses is avoided. The aim of this article is to identify issues for property use arising as a consequence of increased engagement in the internet economy. The article commences by clarifying what is meant by the term ‘internet economy’ before highlighting current impacts of the internet. It concludes by suggesting potential impacts for property and property uses in the future.

Internet Child Abuse: Current Research, Policy and Practice

Internet Child Abuse: Current Research and Policy provides a timely overview of international policy, legislation and offender management and treatment practice in the area of Internet child abuse. Internet use has grown considerably over the last five years, and information technology now forms a core part of the formal education system in many countries. There is however, increasing evidence that the Internet is used by some adults to access children and young people in order to ‘groom’ them for the purposes of sexual abuse; as well as to produce and distribute indecent illegal images of children. This book presents and assesses the most recent and current research on internet child abuse, addressing: its nature, the behaviour and treatment of its perpetrators, international policy, legislation and protection, and policing. It will be required reading for an international audience of academics, researchers, policy-makers and criminal justice practitioners with interests in this area.

Characteristics of the Internet for Criminal Child Sexual Abuse by Online Groomers

This paper presents a number of characteristics of the Internet that makes it attractive to online groomers. Relevant Internet characteristics include disconnected personal communication, mediating technology, universality, network externalities, distribution channel, time moderator, low‐cost standard, electronic double, electronic double manipulation, information asymmetry, infinite virtual capacity, independence in time and space, cyberspace, and dynamic social network. Potential sex offenders join virtual communities, where they meet other persons who have the same interest. A virtual community provides an online meeting place where people with similar interests can communicate and find useful information. Communication between members may be via email, bulletin boards, online chat, web‐based conferencing or other computer‐based media.