47,153 research outputs found
Copyright, Fair Use and the Digital Age in Academic Libraries: A Review of the Literature
Copyright law in the United States has gained a certain notoriety for its complexity and ambiguity, which has only been compounded by the evolution (or, some would say, revolution) of print resources to electronic resources. The purpose of this literature review is to review the current understanding of copyright law within the context of academic libraries in universities and colleges. Additionally, this review will describe what issues academic librarians face in complying with copyright law in this new digital age while continuing to perform duties such as processing course reserve materials, developing an institutional repository, and maintaining a digital collection. This literature review emphasizes the need for further and continuing education about copyright law among all members of the campus community, and, in particular, academic librarians
Studies on the release of neutrophil extracellular traps and IFN-γ as part of the innate immune response to Aspergillus fumigatus and on the fungal stress response via the hybrid sensor kinase TcsC
Aspergillus fumigatus is a saprophytic mold that naturally inhabits the soil. Asexual reproduction yields hardy conidia that circulate in the air and are inhaled daily by humans. The fungus seems not to have evolved distinct mechanisms of pathogenicity, but is capable of responding to many stressful environmental cues present in its naturally harsh niche. The robust conidia present no problem to a fully functioning immune system, but if the innate immune system is compromised, the conidia can become activated and differentiate within the lung tissue to form invasive and disseminating hyphae. The resulting disease is called aspergillosis and is difficult to detect and to treat. To date, scientists have yet to find the factor(s) missing during immunosuppression that allow a healthy patient to easily dispose of A. fumigatus. We explored two possibilities: the production of neutrophil extracellular traps (NETs) and the release of IFN-γ by natural killer (NK) cells. We report here that NETs alone cannot kill the fungus, but do inhibit polar growth. Elongation of hyphal tips is abrogated due to zinc starvation, likely a consequence of the zinc-chelating, NETs-associated protein calprotectin. NK cells alone are also incapable of fungicidal activity, but their release of IFN-γ upon contact with A. fumigatus abrogates hyphal growth by a yet unknown mechanism. In vitro studies of the innate immune response, though helpful, are far from representative of the in vivo response. Neither NETs nor IFN-γ alone can manage Aspergillus infection, but in combination, these and other immune assaults certainly can. The difficulty lies in identifying the precise combination of immune cells and cytokine milieu that in a healthy individual prevent infection.
Additionally, we explored mechanisms by which the fungus responds to stress, namely the HOG MAPK pathway, historically involved in osmotic stress response. In filamentous fungi, certain stress signals are sensed by a cytoplasmic hybrid histidine kinase sensor and then passed through the HOG system via phosphorylation. We identified the putative hybrid sensor kinase in A. fumigatus, and generated a corresponding knockout mutant. The ΔtcsC mutant was indeed sensitive to osmotic stress, and resistant to the phenolpyrrole fungicide fludioxonil. In the wild type the addition of either osmotic stress or fludioxonil resulted in SakA phosphorylation and translocation to the nucleus. SakA, the Hog1 homolog in A. fumigatus, is located at the end of the HOG pathway, confirming the role of TcsC as the cytoplasmic sensor upstream of SakA. In hypoxia, on farnesol, and in high concentrations of divalent cations the ΔtcsC mutant exhibited a striking “fluffy” phenotype characterized by the production of tremendous aerial hyphae and little or no differentiation, i.e., no conidiation. Though the ΔtcsC mutant showed no change in virulence compared to wild type, components of the TcsC signalling pathway remain promising targets for antifungal agents
The asymptotically flat scalar-flat Yamabe problem with boundary
We consider two cases of the asymptotically flat scalar-flat Yamabe problem
on a non-compact manifold with boundary, in dimension . First,
following arguments of Cantor and Brill in the compact case, we show that given
an asymptotically flat metric , there is a conformally equivalent
asymptotically flat scalar-flat metric that agrees with on the boundary. We
then replace the metric boundary condition with a condition on the mean
curvature: Given a function on the boundary that is not too large, we show
that there is an asymptotically flat scalar-flat metric, conformally equivalent
to whose boundary mean curvature is given by . The latter case involves
solving an elliptic PDE with critical exponent using the method of sub- and
supersolutions. Both results require the usual assumption that the Sobolev
quotient is positive.Comment: 10 page
First Law of Black Hole Mechanics as a Condition for Stationarity
In earlier work [arXiv:1302.1237], we provided a Hilbert manifold structure
for the phase space for the Einstein-Yang-Mills equations, and used this to
prove a condition for initial data to be stationary. Here we use the same phase
space to consider the evolution of initial data exterior to some closed
2-surface boundary, and establish a condition for stationarity in this case. It
is shown that the differential relationship given in the first law of black
hole mechanics is exactly the condition required for the initial data to be
stationary; this was first argued non-rigorously by Sudarsky and Wald in 1992.
Furthermore, we give evidence to suggest that if this differential relationship
holds then the boundary surface is the bifurcation surface of a bifurcate
Killing horizon.Comment: 20 page
The Phase Space for the Einstein-Yang-Mills Equations and the First Law of Black Hole Thermodynamics
We use the techniques of Bartnik (2005) to show that the space of solutions
to the Einstein-Yang-Mills constraint equations on an asymptotically at
manifold with one end and zero boundary components, has a Hilbert manifold
structure; the Einstein-Maxwell system can be considered as a special case.
This is equivalent to the property of linearisation stability, which was
studied in depth throughout the 70s. This framework allows us to prove a
conjecture of Sudarsky and Wald (1992), that is, the validity of the first law
of black hole thermodynamics is a suitable condition for stationarity. Since we
work with a single end and no boundary conditions, this is equivalent to
critical points of the ADM mass subject to variations fixing the Yang-Mills
charge corresponding exactly to stationary solutions. The natural extension to
this work is to prove the second conjecture of Sudarsky and Wald, which is the
case where an interior boundary is present; this will be addressed in future
work.Comment: 21 pages; references added. v3: typos corrected, minor formatting
changes. To appear in ATMP, 18(4
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Sustainable Professional Practice
The project aims were to examine the ways in which the two distance learning social work programmes (The Open University (OU)and Charles Sturt University(CSU))
operate - looking at pedagogies and in particular how learning and teaching works in the practicum. Exchange visits were organised with Associate Professor Bowles
spending 10 days at The Open University in June 2009, and Mick McCormick pending time at CSU in August/September 2009.
Our aim was to investigate the different and similar ways in which we approached the teaching of practitioners in social work.
We gained many benefits from our contacts and had opportunity to meet and work with social work academics and input to teaching and learning within respective academic institutions.
Many of our findings are reflected in recently published work, or work in publication. Findings also have an ongoing impact on the production, delivery and review of our respective practice learning social work programmes
Race, Gender, Sexuality, Ability, Identity and Cycling, Blog 5
Student blog posts from the Great VCU Bike Race Book
A note on mass-minimising extensions
A conjecture related to the Bartnik quasilocal mass, is that the infimum of
the ADM energy, over an appropriate space of extensions to a compact 3-manifold
with boundary, is realised by a static metric. It was shown by Corvino [Comm.
Math. Phys. 214(1), (2000)] that if the infimum is indeed achieved, then it is
achieved by a static metric; however, the more difficult question of whether or
not the infimum is achieved, is still an open problem. Bartnik [Comm. Anal.
Geom. 13(5), (2005)] then proved that critical points of the ADM mass, over the
space of solutions to the Einstein constraints on an asymptotically flat
manifold without boundary, correspond to stationary solutions. In that article,
he stated that it should be possible to use a similar construction to provide a
more natural proof of Corvino's result.
In the first part of this note, we discuss the required modifications to
Bartnik's argument to adapt it to include a boundary. Assuming that certain
results concerning a Hilbert manifold structure for the space of solutions
carry over to the case considered here, we then demonstrate how Bartnik's proof
can be modified to consider the simpler case of scalar-flat extensions and
obtain Corvino's result.
In the second part of this note, we consider a space of extensions in a fixed
conformal class. Sufficient conditions are given to ensure that the infimum is
realised within this class.Comment: 17 pages. Substantial changes to Section 3. Updated to agree with
published versio
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