2,008 research outputs found
Data retention, journalist freedoms and whistleblowers
As members of the ‘fourth estate’, journalists have enjoyed certain limited protections for themselves and their sources under the laws of various countries. These protections are now uniquely challenged in the context of metadata retention and enhanced surveillance and national security protections. This article examines the recent changes to laws in Australia and the position of journalists as investigative watchdogs. It considers the nature of the new laws, the responses of journalists, the broader context of commercial journalism and the rise of the infotainment business model, and the role of the ‘networked fourth estate’ and non-institutional actors in creating accountable government in Australia.Sal Humphreys, Melissa de Zwar
The Evolution of Globular Clusters in the Galaxy
We investigate the evolution of globular clusters using N-body calculations
and anisotropic Fokker-Planck (FP) calculations. The models include a mass
spectrum, mass loss due to stellar evolution, and the tidal field of the parent
galaxy. Recent N-body calculations have revealed a serious discrepancy between
the results of N-body calculations and isotropic FP calculations. The main
reason for the discrepancy is an oversimplified treatment of the tidal field
employed in the isotropic FP models. In this paper we perform a series of
calculations with anisotropic FP models with a better treatment of the tidal
boundary and compare these with N-body calculations. The new tidal boundary
condition in our FP model includes one free parameter. We find that a single
value of this parameter gives satisfactory agreement between the N-body and FP
models over a wide range of initial conditions.
Using the improved FP model, we carry out an extensive survey of the
evolution of globular clusters over a wide range of initial conditions varying
the slope of the mass function, the central concentration, and the relaxation
time. The evolution of clusters is followed up to the moment of core collapse
or the disruption of the clusters in the tidal field of the parent galaxy. In
general, our model clusters, calculated with the anisotropic FP model with the
improved treatment for the tidal boundary, live longer than isotropic models.
The difference in the lifetime between the isotropic and anisotropic models is
particularly large when the effect of mass loss via stellar evolution is rather
significant. On the other hand the difference is small for relaxation-
dominated clusters which initially have steep mass functions and high central
concentrations.Comment: 36 pages, 11 figures, LaTeX; added figures and tables; accepted by
Ap
Mutation supply and the repeatability of selection for antibiotic resistance
Whether evolution can be predicted is a key question in evolutionary biology.
Here we set out to better understand the repeatability of evolution. We
explored experimentally the effect of mutation supply and the strength of
selective pressure on the repeatability of selection from standing genetic
variation. Different sizes of mutant libraries of an antibiotic resistance
gene, TEM-1 -lactamase in Escherichia coli, were subjected to different
antibiotic concentrations. We determined whether populations went extinct or
survived, and sequenced the TEM gene of the surviving populations. The
distribution of mutations per allele in our mutant libraries- generated by
error-prone PCR- followed a Poisson distribution. Extinction patterns could be
explained by a simple stochastic model that assumed the sampling of beneficial
mutations was key for survival. In most surviving populations, alleles
containing at least one known large-effect beneficial mutation were present.
These genotype data also support a model which only invokes sampling effects to
describe the occurrence of alleles containing large-effect driver mutations.
Hence, evolution is largely predictable given cursory knowledge of mutational
fitness effects, the mutation rate and population size. There were no clear
trends in the repeatability of selected mutants when we considered all
mutations present. However, when only known large-effect mutations were
considered, the outcome of selection is less repeatable for large libraries, in
contrast to expectations. Furthermore, we show experimentally that alleles
carrying multiple mutations selected from large libraries confer higher
resistance levels relative to alleles with only a known large-effect mutation,
suggesting that the scarcity of high-resistance alleles carrying multiple
mutations may contribute to the decrease in repeatability at large library
sizes.Comment: 31pages, 9 figure
Piracy vs. control: models of virtual world governance and their impact on player and user experience
Current models of governance of virtual worlds evolved from the Terms of Service developed by the virtual world content creators based upon intellectual property license models. Increasingly, however virtual world providers now seek to accommodate both the needs and interests of owners and users in order to respond to the evolving needs of the virtual world. However, domestic governments are also now taking greater interest in the activities within virtual communities. This article explores a range of governance models, and the competing interests at play within the virtual communities managed by such models, in order to consider whether there is a universally adaptable governance model. In particular it analyses the role and effectiveness of the Council of Stellar Management, the player representative committee in EVE. The article concludes that national governments should not impose significant regulation upon virtual communities, but rather should encourage the development and growth of such communities by prescribing minimum standards, such as standardisation and transparency of Terms of Service. Matters occurring within the virtual world environment should be dealt with in accordance with the established community norms and rules. Therefore, role play environments such as EVE should be allowed to encourage piratical and outlaw behaviour without offending domestic laws.Melissa de Zwar
ACCE submission to public consultation to "enhancing online safety for children"
This paper investigates the place of trust in a school context and its importance in achieving the aims of schooling, “namely high academic performance and positive affects among members of the school community” (Forsyth, 2008). The role of trust in the use of technology and technological change is examined. Literature is surveyed in the fields of trust in the school community and trends that are impacting technology use in schools. The concept of collaborative and participatory culture in particular is examined. Digital citizenship is presented as a necessary component of an educational technology program. Some general suggestions for developing a culture of trust are presented.Michael Henderson, Melissa de Zwar
WI-FI in the ivory tower: reducing isolation of the law PhD student through social media networks
This paper was presented at the 2013 National Wellness for Law Forum, 21 – 22 February 2013.Research students no longer need to spend long hours on campus under the gaze of their supervisors. Ubiquitous access to online databases and communication tools means that many PhD students operate in splendid isolation, away from the bustle and distractions of campus life. But this freedom may also bring with it strong feelings of isolation from academic community and peer support. The authors of this study have commenced an inquiry into whether the connectivity and interactivity of social media can provide a vital social lifeline for research students (particularly law students who work largely independently and are not frequently part of large research teams) in order to address these feelings of isolation. The role of social media in shaping academic identity and voice is also addressed. It considers a number of significant UK studies of higher degree by research students and their relevance for Australia and outlines the results of a small pilot survey conducted in an Australian law school.Melissa de Zwart, Bernadette Richard
Monitoring Energiebesparing door Het Nieuwe Telen en Energie-innovaties
In recent years, new technologies and cultivation methods have been developed to contribute to an energyefficientgreenhouse horticulture sector. In the monitoring project, the performance of these systems has beenassessed objectively by comparing similar greenhouses or greenhouse compartments with and without thesetechniques. Due to the long-term character of the project, a learning process of growers in the application ofthese systems can now be studied. For those cases, some growers have been followed for successive years.The output of the monitoring project consists of reports and a large number of blogs, vlogs, articles in growermagazinesand presentations horticultural events.This document provides a general review of the results from the entire project and draws general conclusions.For detailed information on the different systems, reference is made to specific outputs of the project.The energy savings potential of Next Generation Greenhouse Cultivation and Energy Innovations proves to begreat. The application of different options, however, depends strongly on the economic conditions and the resultsdepend also on the skills, experience and focus of the growers in managing their greenhouse climate
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