8,026 research outputs found
Rethinking Australia’s International Past: Identity, Foreign Policy and India in the Australian Colonial Imagination
This article examines the ways in which Australia’s global connections during the colonial period have shaped its contemporary international political identity and the implications of such an approach for the study of Australian foreign policy and international relations (IR). This is particularly pertinent due to recent historiographical reconceptualization of nineteenth century colonial networks, which suggest Australia’s connections to India are far more important than previously considered. These issues are explored through a case study of Australia’s links with India prior to Federation, employing a discursive analysis of public debate on utilizing Indian indentured laborers in tropical Northern Australia
Static and Dynamic Properties of Type-II Composite Fermion Wigner Crystals
The Wigner crystal of composite fermions is a strongly correlated state of
complex emergent particles, and therefore its unambiguous detection would be of
significant importance. Recent observation of optical resonances in the
vicinity of filling factor {\nu} = 1/3 has been interpreted as evidence for a
pinned Wigner crystal of composite fermions [Zhu et al., Phys. Rev. Lett. 105,
126803 (2010)]. We evaluate in a microscopic theory the shear modulus and the
magnetophonon and magnetoplasmon dispersions of the composite fermion Wigner
crystal in the vicinity of filling factors 1/3, 2/5, and 3/7. We determine the
region of stability of the crystal phase, and also relate the frequency of its
pinning mode to that of the corresponding electron crystal near integer
fillings. These results are in good semiquantitative agreement with experiment,
and therefore support the identification of the optical resonance as the
pinning mode of the composite fermions Wigner crystal. Our calculations also
bring out certain puzzling features, such as a relatively small melting
temperature for the composite fermion Wigner crystal, and also suggest a higher
asymmetry between Wigner crystals of composite fermion particles and holes than
that observed experimentally.Comment: Composite Fermion Wigner Crystal; 14 pages, 9 figure
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Design and Benchmark Testing for Open Architecture Reconfigurable Mobile Spirometer and Exhaled Breath Monitor with GPS and Data Telemetry.
Portable and wearable medical instruments are poised to play an increasingly important role in health monitoring. Mobile spirometers are available commercially, and are used to monitor patients with advanced lung disease. However, these commercial monitors have a fixed product architecture determined by the manufacturer, and researchers cannot easily experiment with new configurations or add additional novel sensors over time. Spirometry combined with exhaled breath metabolite monitoring has the potential to transform healthcare and improve clinical management strategies. This research provides an updated design and benchmark testing for a flexible, portable, open access architecture to measure lung function, using common Arduino/Android microcontroller technologies. To demonstrate the feasibility and the proof-of-concept of this easily-adaptable platform technology, we had 43 subjects (healthy, and those with lung diseases) perform three spirometry maneuvers using our reconfigurable device and an office-based commercial spirometer. We found that our system compared favorably with the traditional spirometer, with high accuracy and agreement for forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC), and gas measurements were feasible. This provides an adaptable/reconfigurable open access "personalized medicine" platform for researchers and patients, and new chemical sensors and other modular instrumentation can extend the flexibility of the device in the future
wormholes and topological charge
I investigate solutions to the Euclidean Einstein-matter field equations with
topology in a theory with a massless periodic scalar
field and electromagnetism. These solutions carry winding number of the
periodic scalar as well as magnetic flux. They induce violations of a
quasi-topological conservation law which conserves the product of magnetic flux
and winding number on the background spacetime. I extend these solutions to a
model with stable loops of superconducting cosmic string, and interpret them as
contributing to the decay of such loops.Comment: 18 pages (includes 6 figs.), harvmac and epsf, CU-TP-62
Quantum tunneling of superconducting string currents
We investigate the decay of current on a superconducting cosmic string
through quantum tunneling. We construct the instanton describing tunneling in a
simple bosonic string model, and estimate the decay rate. The tunneling rate
vanishes in the limit of a chiral current. This conclusion, which is supported
by a symmetry argument, is expected to apply in general. It has important
implications for the stability of chiral vortons.Comment: 16 pages, 2 figure
Walking the Thin Line: India's Anti-Racist Diplomatic Practice in South Africa, Canada, and Australia, 1946–55
Historians of India's foreign policy have often failed to see beyond the ‘Great man’ Jawaharlal Nehru. This Nehru-centric vision is not only misleading, but also unfair to Nehru. Here, we seek to take the gaze off Nehru and New Delhi so as to view Indian foreign policy from different locations. We examine the ways in which India's diplomats in Australia, Canada, and South Africa resisted racial discrimination. India's anti-racist diplomacy has most often been viewed as pointless moralistic ranting: the domain of the ‘hypersensitive, emotional’ Indian. We argue, however, based on largely unexamined archival material and an emphasis on the practice of Indian diplomacy, that India's diplomats in these bastions of settler-colonial racism were tactful, strategic, and effective in challenging racist, colonial practices and bringing an anti-racist discourse to international politics. Nehruvian foreign-policy discourse, and its goal of an anti-racist world order, then, was tempered by its diplomatic practices. In particular, this occurred outside of New Delhi in places where India's hopes for productive international relationships clashed with its Nehruvian worldview
Stability of Solution of the Nonlinear Schr\"odinger Equation for the Bose-Einstein Condensation
We investigate the stability of the Bose-Einstein condensate (BEC) the case
of atoms with negative scattering lengths at zero temperature using the
Ginzburg-Pitaevskii-Gross (GPG) stationary theory. We have found a new exact
equation for determining the upper bound of the critical numbers of
atoms for a metastable state to exist. Our calculated value of for
Bose-Einstein condensation of lithium atoms based on our new equation is in
agreement with those observed in a agreement with those observed in a recent
experiment.Comment: 8 pages, Late
Synthetic blends of volatile, phytopathogen-induced odorants can be used to manipulate vector behavior
Volatile organic compounds (VOCs) are emitted from all plants and these VOCs are important means of communication between plants and insects. It has been documented that pathogen infections alter VOC profiles rendering infected plants more attractive to specific vectors transmitting these pathogens than uninfected plants, thus potentially aiding in pathogen propagation. Mimicking these chemical cues might enable insect attraction away from the plant or disruption of host finding behavior of the vector. However, the practical implications have not been fully explored. We used citrus, Diaphorina citri and huanglongbing (HLB) as a model host-vector-disease system because HLB threatens citrus production worldwide and is similar to other critical diseases of food crops, such as Zebra Chip affecting potato. We formulated a synthetic chemical blend using selected HLB-specific biomarker compounds, and tested the blend with the Attenu assay system for chemosensory proteins. The Attenu assay system is a procedure that identifies interactions between insect chemosensory proteins and their ligands. We found that an equimolar mixture of compounds mimicking the volatile profile of HLB-infected citrus bound chemosensory proteins. Further investigation of this blend in laboratory behavioral assays resulted in development of a synthetic lure that was more attractive to D. citri than natural citrus tree volatiles. This strategy could provide a new route to produce chemical lures for vector population control for a variety of plant and/or animal systems and it may result in the development of a practical lure for monitoring vectors of disease, such as D. citri
AEGIS-X: The Chandra Deep Survey of the Extended Groth Strip
We present the AEGIS-X survey, a series of deep Chandra ACIS-I observations
of the Extended Groth Strip. The survey comprises pointings at 8 separate
positions, each with nominal exposure 200ks, covering a total area of
approximately 0.67 deg2 in a strip of length 2 degrees. We describe in detail
an updated version of our data reduction and point source detection algorithms
used to analyze these data. A total of 1325 band-merged sources have been found
to a Poisson probability limit of 4e-6, with limiting fluxes of 5.3e-17
erg/cm2/s in the soft (0.5-2 keV) band and 3.8e-16 erg/cm2/s in the hard (2-10
keV) band. We present simulations verifying the validity of our source
detection procedure and showing a very small, <1.5%, contamination rate from
spurious sources. Optical/NIR counterparts have been identified from the DEEP2,
CFHTLS, and Spitzer/IRAC surveys of the same region. Using a likelihood ratio
method, we find optical counterparts for 76% of our sources, complete to
R(AB)=24.1, and, of the 66% of the sources that have IRAC coverage, 94% have a
counterpart to a limit of 0.9 microJy at 3.6 microns (m(AB)=23.8). After
accounting for (small) positional offsets in the 8 Chandra fields, the
astrometric accuracy of the Chandra positions is found to be 0.8 arcsec RMS,
however this number depends both on the off-axis angle and the number of
detected counts for a given source. All the data products described in this
paper are made available via a public website.Comment: 17 pages, 9 figures. Accepted for publication in ApJS. Data products
are available at http://astro.imperial.ac.uk/research/aegis
Morphing Ensemble Kalman Filters
A new type of ensemble filter is proposed, which combines an ensemble Kalman
filter (EnKF) with the ideas of morphing and registration from image
processing. This results in filters suitable for nonlinear problems whose
solutions exhibit moving coherent features, such as thin interfaces in wildfire
modeling. The ensemble members are represented as the composition of one common
state with a spatial transformation, called registration mapping, plus a
residual. A fully automatic registration method is used that requires only
gridded data, so the features in the model state do not need to be identified
by the user. The morphing EnKF operates on a transformed state consisting of
the registration mapping and the residual. Essentially, the morphing EnKF uses
intermediate states obtained by morphing instead of linear combinations of the
states.Comment: 17 pages, 7 figures. Added DDDAS references to the introductio
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