966 research outputs found
On the performance of West's bubble test: A simulation approach
Cataloged from PDF version of article.In this research we examine the ability of Westâs bubble test [1] in detecting speculative
bubbles using Brockâs (1982) [2] intertemporal general equilibrium model of asset pricing
as the basis for a simulation study. In this setting, (1) the economy, by construction is effi-
cient and produces the maximally possible amount of welfare for society, and (2) asset
prices reflect the utility-maximizing behavior of consumers and the profit-maximizing
behavior of firms. We find that the Westâs bubble test flag as ââbubblesâ in the simulated
data yet the data is produced from an economy in which markets are efficient in welfare
production
A Survey About Nothing: Monitoring a Million Supergiants for Failed Supernovae
Extragalactic transient searches have historically been limited to looking
for the appearance of new sources such as supernovae. It is now possible to
carry out a new kind of survey that will do the opposite, that is, search for
the disappearance of massive stars. This will entail the systematic observation
of galaxies within a distance of 10 Mpc in order to watch ~10^6 supergiants.
Reaching this critical number ensures that something will occur yearly, since
these massive stars must end their lives with a core collapse within ~10^6
years. Using deep imaging and image subtraction it is possible to determine the
fates of these stars whether they end with a bang (supernova) or a whimper
(fall out of sight). Such a survey would place completely new limits on the
total rate of all core collapses, which is critical for determining the
validity of supernova models. It would also determine the properties of
supernova progenitors, better characterize poorly understood optical
transients, such as eta Carina-like mass ejections, find and characterize large
numbers of Cepheids, luminous blue variables and eclipsing binaries, and allow
the discovery of any new phenomena that inhabit this relatively unexplored
parameter space.Comment: final version, 7 pages, 5 figures, ApJ in pres
Gratitude: Does it have a place within media-practice education?
Gratitude may be an important yet largely untapped aspect of media-practice education. This research uses an exploratory approach with media-practice academics and students in order to examine the evidence and nature of gratitude within media-practice education. Given the exploratory nature of the study, interim findings are reported. The research finds media-practice students to be open to gratitude having a place within their educational experiences, indeed students exclusively speak about situations in which they feel grateful, as positive aspects of their student experience. However academics see gratitude in a more varied way. For some, gratitude and its cyclical nature resonate; for others, gratitude is inappropriate and loaded with notions of power. These different perspectives may be partially explained by the different ways in which students and academics perceive gratitude. Whereas initial student voices suggest that gratitude is a positive emotion associated with a desire to reciprocate, academicsâ interpretation seems to emphasise obligation. This mismatch may inhibit the current impact of gratitude within the media-practice learning context. The research suggests that gratitude may be a defining aspect of a functional, productive student experience which those working within media-practice education might usefully aim to generate
Role of IRAK-M in Alcohol Induced Liver Injury
Increasing evidence suggests that innate immunity plays an important role in alcohol-induced liver injury and most studies have focused on positive regulation of innate immunity. The main objective of this study was to investigate the negative regulator of innate immunity, IL-1/Toll-like receptor (TLR) signaling pathways and interleukin receptor-associated kinase-M (IRAK-M) in alcoholic liver injury. We established an alcohol-induced liver injury model using wild type and IRAK-M deficient B6 mice and investigated the possible mechanisms. We found that in the absence of IRAK-M, liver damage by alcohol was worse with higher alanine transaminase (ALT), more immune cell infiltration and increased numbers of IFNÎł producing cells. We also found enhanced phagocytic activity in CD68+ cells. Moreover, our results revealed altered gut bacteria after alcohol consumption and this was more striking in the absence of IRAK-M. Our study provides evidence that IRAK-M plays an important role in alcohol-induced liver injury and IRAK-M negatively regulates the innate and possibly the adaptive immune response in the liver reacting to acute insult by alcohol. In the absence of IRAK-M, the hosts developed worse liver injury, enhanced gut permeability and altered gut microbiota
Rapid quantitative assays for glucose-6-phosphate dehydrogenase (G6PD) and hemoglobin combined on a capillary-driven microfluidic chip
Rapid tests for glucose-6-phosphate dehydrogenase (G6PD) are extremely important for determining G6PD deficiency, a widespread metabolic disorder which triggers hemolytic anemia in response to primaquine and tafenoquine medication, the most effective drugs for the radical cure of malaria caused by Plasmodium parasites. Current point-of-care diagnostic devices for G6PD are either qualitative, do not normalize G6PD activity to the hemoglobin concentration, or are very expensive. In this work we developed a capillary-driven microfluidic chip to perform a quantitative G6PD test and a hemoglobin measurement within 2 minutes and using less than 2 ÎŒL of sample. We used a powerful microfluidic module to integrate and resuspend locally the reagents needed for the G6PD assay and controls. We also developed a theoretical model that successfully predicts the enzymatic reactions on-chip, guides on-chip reagent spotting and allows efficient integration of multiple assays in miniaturized formats with only a few nanograms of reagents
The tumour bank at the children's hospital at westmead: An Australian paediatric cancer biorepository
© 2018 The Author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International License (CC-BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. See http://creativecommons.org/licenses/by/4.0/. The Tumor Bank at The Children's Hospital at Westmead was established in 1998 with the purpose of facilitating research into childhood malignancy through the active provision of well annotated, ethically collected tissue samples and providing a pathway for the Children Hospital at Westmead to engage in leading research initiatives, supporting international investigations and clinical trials. Within 20 years practice as a single institute biorepository, The Tumour Bank has established standard operating procedures for collection of tissue, blood and bone marrow that were integrated into routine patient management systems. In addition, three main operational areas have been developed: collection of biospecimens and written consent; management of clinical data and biospecimen inventory database; and implementation of an open access policy to support childhood cancer research around the world. Regulatory oversight is provided by the Tumour Bank Committee, Human Research Ethics Committee and Governance Department. This concerted effort has resulted in collecting 20340 specimens from 3788 patients within 20 years, and The Tumour bank has supported over 108 national and international research projects, and contributed to over 70 peer-reviewed publications to date, with a mean time-to-publication of 19.1 ± 9.0 months and average Impact Factor of 6.11 ± 4.53. In conclusion, the Children's Hospital at Westmead Tumour Bank has demonstrated a sustained single institutional biorepository model for facilitating translational research of rare cancer. It has provided strong evidence that integration of a single institutional biobank into standard clinical practices would be the long-term pathway of valuable bio-resource for rare cancer research
End-to-End Joint Antenna Selection Strategy and Distributed Compress and Forward Strategy for Relay Channels
Multi-hop relay channels use multiple relay stages, each with multiple relay
nodes, to facilitate communication between a source and destination.
Previously, distributed space-time codes were proposed to maximize the
achievable diversity-multiplexing tradeoff, however, they fail to achieve all
the points of the optimal diversity-multiplexing tradeoff. In the presence of a
low-rate feedback link from the destination to each relay stage and the source,
this paper proposes an end-to-end antenna selection (EEAS) strategy as an
alternative to distributed space-time codes. The EEAS strategy uses a subset of
antennas of each relay stage for transmission of the source signal to the
destination with amplify and forwarding at each relay stage. The subsets are
chosen such that they maximize the end-to-end mutual information at the
destination. The EEAS strategy achieves the corner points of the optimal
diversity-multiplexing tradeoff (corresponding to maximum diversity gain and
maximum multiplexing gain) and achieves better diversity gain at intermediate
values of multiplexing gain, versus the best known distributed space-time
coding strategies. A distributed compress and forward (CF) strategy is also
proposed to achieve all points of the optimal diversity-multiplexing tradeoff
for a two-hop relay channel with multiple relay nodes.Comment: Accepted for publication in the special issue on cooperative
communication in the Eurasip Journal on Wireless Communication and Networkin
Damping of supernova neutrino transitions in stochastic shock-wave density profiles
Supernova neutrino flavor transitions during the shock wave propagation are
known to encode relevant information not only about the matter density profile
but also about unknown neutrino properties, such as the mass hierarchy (normal
or inverted) and the mixing angle theta_13. While previous studies have
focussed on "deterministic" density profiles, we investigate the effect of
possible stochastic matter density fluctuations in the wake of supernova shock
waves. In particular, we study the impact of small-scale fluctuations on the
electron (anti)neutrino survival probability, and on the observable spectra of
inverse-beta-decay events in future water-Cherenkov detectors. We find that
such fluctuations, even with relatively small amplitudes, can have significant
damping effects on the flavor transition pattern, and can partly erase the
shock-wave imprint on the observable time spectra, especially for
sin^2(theta_13) > O(10^-3).Comment: v2 (23 pages, including 6 eps figures). Typos removed, references
updated, matches the published versio
On possible interpretations of the high energy electron-positron spectrum measured by the Fermi Large Area Telescope
The Fermi-LAT experiment recently reported high precision measurements of the
spectrum of cosmic-ray electrons-plus-positrons (CRE) between 20 GeV and 1 TeV.
The spectrum shows no prominent spectral features, and is significantly harder
than that inferred from several previous experiments. Here we discuss several
interpretations of the Fermi results based either on a single large scale
Galactic CRE component or by invoking additional electron-positron primary
sources, e.g. nearby pulsars or particle Dark Matter annihilation. We show that
while the reported Fermi-LAT data alone can be interpreted in terms of a single
component scenario, when combined with other complementary experimental
results, specifically the CRE spectrum measured by H.E.S.S. and especially the
positron fraction reported by PAMELA between 1 and 100 GeV, that class of
models fails to provide a consistent interpretation. Rather, we find that
several combinations of parameters, involving both the pulsar and dark matter
scenarios, allow a consistent description of those results. We also briefly
discuss the possibility of discriminating between the pulsar and dark matter
interpretations by looking for a possible anisotropy in the CRE flux.Comment: 29 pages, 12 figures. Final version accepted for publication in
Astroparticle Physic
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