2,944 research outputs found
New Media, First Time Voters and the 2007 Australian Federal Election
Researchers suggest that the youth of today has disengaged from the political landscape in Australia. However, the online realm provides potential first time voters an avenue in which to engage in politics in an environment that is generally associated with a youthful demographic. New media tactics utilised during the 2007 Australian federal election aimed to not only attract youthful voters, but also to educate and deliver policy on a level generally associated with the 18-24 demographic. This study explored the effectiveness of new media in the political communication context, in particular with relation to first time voters. This research found that first time voters were not as engaged as predicted, and that the third party sites were more popular with undecided voters than the formal political party sites in voter influence
New nuclear three-body clusters \phi{NN}
Binding energies of three-body systems of the type \phi+2N are estimated. Due
to the strong attraction between \phi-meson and nucleon, suggested in different
approaches, bound states can appear in systems like \phi+np (singlet and
triplet) and \phi+pp. This indicates the principal possibility of the formation
of new nuclear clusters
Sub-luminous type Ia supernovae from the mergers of equal-mass white dwarfs with M~0.9 M_sun
Type Ia supernovae (SNe Ia) are thought to result from thermonuclear
explosions of carbon-oxygen white dwarf stars. Existing models generally
explain the observed properties, with the exception of the sub-luminous
1991-bg-like supernovae. It has long been suspected that the merger of two
white dwarfs could give rise to a type Ia event, but hitherto simulations have
failed to produce an explosion. Here we report a simulation of the merger of
two equal-mass white dwarfs that leads to an underluminous explosion, though at
the expense of requiring a single common-envelope phase, and component masses
of ~0.9 M_sun. The light curve is too broad, but the synthesized spectra, red
colour and low expansion velocities are all close to what is observed for
sub-luminous 1991bg-like events. While mass ratios can be slightly less than
one and still produce an underluminous event, the masses have to be in the
range 0.83-0.9 M_sun.Comment: Accepted to Natur
Risk factors for delay in symptomatic presentation of leukaemia, lymphoma and myeloma
Background: UK policy aims to improve cancer outcomes by promoting early diagnosis, which for many haematological malignancies is particularly challenging as the pathways leading to diagnosis can be difficult and prolonged.
Methods: A survey about symptoms was sent to patients in England with acute leukaemia, chronic lymphocytic leukaemia (CLL), chronic myeloid leukaemia (CML), myeloma and non-Hodgkin lymphoma (NHL). Symptoms and barriers to first help seeking were examined for each subtype, along with the relative risk of waiting >3 months’ time from symptom onset to first presentation to a doctor, controlling for age, sex and deprivation.
Results: Of the 785 respondents, 654 (83.3%) reported symptoms; most commonly for NHL (95%) and least commonly for CLL (67.9%). Some symptoms were frequent across diseases while others were more disease-specific. Overall, 16% of patients (n=114) waited >3 months before presentation; most often in CML (24%) and least in acute leukaemia (9%). Significant risk factors for >3 months to presentation were: night sweats (particularly CLL and NHL), thirst, abdominal pain/discomfort, looking pale (particularly acute leukaemias), and extreme fatigue/tiredness (particularly CML and NHL); and not realising symptom(s) were serious.
Conclusions: These findings demonstrate important differences by subtype, which should be considered in strategies promoting early presentation. Not realising the seriousness of some symptoms indicates a worrying lack of public awareness
Type Ia Supernovae as Stellar Endpoints and Cosmological Tools
Empirically, Type Ia supernovae are the most useful, precise, and mature
tools for determining astronomical distances. Acting as calibrated candles they
revealed the presence of dark energy and are being used to measure its
properties. However, the nature of the SN Ia explosion, and the progenitors
involved, have remained elusive, even after seven decades of research. But now
new large surveys are bringing about a paradigm shift --- we can finally
compare samples of hundreds of supernovae to isolate critical variables. As a
result of this, and advances in modeling, breakthroughs in understanding all
aspects of SNe Ia are finally starting to happen.Comment: Invited review for Nature Communications. Final published version.
Shortened, update
A new species of Brachycephalus (Anura:Brachycephalidae) fromthe Quiriri mountain range of southern Brazil
A new miniaturized toadled of the genus Brachycephalus (Anura: Brachycephalidae) is described from Serra do Quiriri in the municipality of Campo Alegre, Santa Catarina, southern Brazil. Specimens were collected from the leaf litter between from 1,263 and 1,318 m above sea level. The new species is distinguished from all its congeners by the combination of the following characters: snout–vent length 9.9–13.1 mm; skin on head and dorsum without dermal co-ossification; snout mucronate in dorsal view; dorsum rugose; general color brown, with a narrow orange vertebral stripe. The region where the new species is located is also shared with other endemic anuran species and has experienced strong anthropogenic impacts,suggesting that immediate actions should be taken to ensure their long-term preservation
Granular Impact: A Grain-scale Approach
This work summarizes a series of studies on two-dimensional granular impact,
where an intruding object strikes a granular material at high speed. Many
previous studies on granular impact have used a macroscopic force law, which is
dominated by an inertial drag term proportional to the intruder velocity
squared. The primary focus here is on the microscopic force response of the
granular material, and how the grain-scale effects give rise to this inertial
drag term. We show that the inertial drag arises from intermittent collisions
with force-chain-like structures. We construct a simple collisional model to
explain the inertial drag, as well as off-axis instability and rotations.
Finally, we show how the granular response changes when the intruder speed
approaches , leading to a failure of the inertial drag description in
this regime. Here, is the mean particle diameter and the
characteristic momentum-transfer time between two grains.Comment: This is draft version of a book chapter appearing in "Rapid
Penetration into Granular Media" (eds. Iskander et al.
The correlation between C/O ratio, metallicity and the initial WD mass for SNe Ia
In this paper, we want to check whether or not the carbon abundance can be
affected by initial metallicity. We calculated a series of stellar evolution.
We found that when , the carbon abundance is almost independent of
metallicity if it is plotted against the initial WD mass. However, when
, the carbon abundance is not only a function of the initial WD mass,
but also metallicity, i.e. for a given initial WD mass, the higher the
metallicity, the lower the carbon abundance. Based on some previous studies,
i.e. both a high metallicity and a low carbon abundance lead to a lower
production of Ni formed during SN Ia explosion, the effects of the
carbon abundance and the metallicity on the amount of Ni are
enhanced by each other, which may account for the variation of maximum
luminosity of SNe Ia, at least qualitatively. Considering that the central
density of WD before supernova explosion may also play a role on the production
of Ni and the carbon abundance, the metallicity and the central
density are all determined by the initial parameters of progenitor system, i.e.
the initial WD mass, metallicity, orbital period and secondary mass, the amount
of Ni might be a function of the initial parameters. Then, our
results might construct a bridge linking the progenitor model and the explosion
model of SNe Ia.Comment: 7pages, 4 figures, accepted for publication in A&
Diversity of supernovae Ia determined using equivalent widths of Si II 4000
Spectroscopic and photometric properties of low and high-z supernovae Ia (SNe
Ia) have been analyzed in order to achieve a better understanding of their
diversity and to identify possible SN Ia sub-types. We use wavelet transformed
spectra in which one can easily measure spectral features. We investigate the
\ion{Si}{II} 4000 equivalent width (EW_w\lbrace\ion{Si}{II}\rbrace). The
ability and, especially, the ease in extending the method to SNe at high- is
demonstrated. We applied the method to 110 SNe Ia and found correlations
between EW_w\lbrace\ion{Si}{II}\rbrace and parameters related to the
light-curve shape for 88 supernovae with available photometry. No evidence for
evolution of EW_w\lbrace\ion{Si}{II}\rbrace with redshift is seen. Three
sub-classes of SNe Ia were confirmed using an independent cluster analysis with
only light-curve shape, colour, and EW_w\lbrace\ion{Si}{II}\rbrace. SNe from
high- samples seem to follow a similar grouping to nearby objects. The
EW_w\lbrace\ion{Si}{II}\rbrace value measured on a single spectrum may point
towards SN Ia sub-classification, avoiding the need for expansion velocity
gradient calculations.Comment: 12 pages, 5 figure
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