3,226 research outputs found
Giant frequency-selective near-field energy transfer in active--passive structures
We apply a fluctuation electrodynamics framework in combination with
semianalytical (dipolar) approximations to study amplified spontaneous energy
transfer (ASET) between active and passive bodies. We consider near-field
energy transfer between semi-infinite planar media and spherical structures
(dimers and lattices) subject to gain, and show that the combination of loss
compensation and near-field enhancement (achieved by the proximity, enhanced
interactions, and tuning of subwavelength resonances) in these structures can
result in orders of magnitude ASET enhancements below the lasing threshold. We
examine various possible geometric configurations, including realistic
materials, and describe optimal conditions for enhancing ASET, showing that the
latter depends sensitively on both geometry and gain, enabling efficient and
tunable gain-assisted energy extraction from structured surfaces
Topical tacrolimus 0.1% ointment for treatment of cutaneous Crohn's Disease
Peer reviewedPublisher PD
Misconduct resistance: the management of restricted drugs in the Western Australian public health service
We employ institutional theory to develop and present a framework – involving institutional drivers, organisational reactions, and outcomes – to examine and further understand misconduct resistance in public sector organisations. This framework is applied to an examination of efforts in the Western Australian public health service to prevent misconduct in the management of restricted drugs. We begin by clarifying a definition of misconduct resistance and then synthesise the extant literature develop a typology and framework of corruption resistance. The second part of the paper is a study in which the framework is applied to an examination of why and how the Western Australian public health service has endeavoured to prevent misconduct in the management of restricted drugs. Top-down imposition of regulations rather than shifts in individual employee attitudes is found. The paper concludes by outlining the potential contributions to theory and practice in approaches to increasing misconduct resistance in public health care organisations
The lightest neutralino in the MNSSM
We examine the allowed mass range of the lightest neutralino within the
Minimal Non--minimal Supersymmetric Standard Model. Being absolutely stable if
R-parity is conserved this lightest neutralino is a candidate for the dark
matter of the universe. We establish the theoretical upper bound on the
lightest neutralino mass and obtain an approximate solution for this mass.Comment: Submitted for the SUSY07 proceedings, 4 pages, LaTeX, 3 eps figures,
some minor changes to the tex
How Can Active Region Plasma Escape into the Solar Wind from below a Closed Helmet Streamer?
Recent studies show that active-region (AR) upflowing plasma, observed by the
EUV-Imaging Spectrometer (EIS), onboard Hinode, can gain access to open
field-lines and be released into the solar wind (SW) via magnetic-interchange
reconnection at magnetic null-points in pseudo-streamer configurations. When
only one bipolar AR is present on the Sun and it is fully covered by the
separatrix of a streamer, such as AR 10978 in December 2007, it seems unlikely
that the upflowing AR plasma can find its way into the slow SW. However,
signatures of plasma with AR composition have been found at 1 AU by Culhane et
al. (2014) apparently originating from the West of AR 10978. We present a
detailed topology analysis of AR 10978 and the surrounding large-scale corona
based on a potential-field source-surface (PFSS) model. Our study shows that it
is possible for the AR plasma to get around the streamer separatrix and be
released into the SW via magnetic reconnection, occurring in at least two main
steps. We analyse data from the Nan\c{c}ay Radioheliograph (NRH) searching for
evidence of the chain of magnetic reconnections proposed. We find a noise storm
above the AR and several varying sources at 150.9 MHz. Their locations suggest
that they could be associated with particles accelerated during the first-step
reconnection process and at a null point well outside of the AR. However, we
find no evidence of the second-step reconnection in the radio data. Our results
demonstrate that even when it appears highly improbable for the AR plasma to
reach the SW, indirect channels involving a sequence of reconnections can make
it possible.Comment: 26 pages, 10 figures. appears in Solar Physics, 201
Protons associated with centers of solar activity and their propagation in interplanetary magnetic field regions co-rotating with the sun
Protons associated with centers of solar activity and propagation in interplanetary magnetic field regions co-rotating with su
Proteasome Lid Bridges Mitochondrial Stress with Cdc53/Cullin1 NEDDylation Status
Cycles of Cdc53/Cullin1 rubylation (a.k.a NEDDylation) protect ubiquitin-E3 SCF (Skp1-Cullin1-F-box protein) complexes from self-destruction and play an important role in mediating the ubiquitination of key protein substrates involved in cell cycle progression, development, and survival. Cul1 rubylation is balanced by the COP9 signalosome (CSN), a multi-subunit derubylase that shows 1:1 paralogy to the 26 S proteasome lid. The turnover of SCF substrates and their relevance to various diseases is well studied, yet, the extent by which environmental perturbations influence Cul1 rubylation/derubylation cycles per se is still unclear. In this study, we show that the level of cellular oxidation serves as a molecular switch, determining Cullin1 rubylation/derubylation ratio. We describe a mutant of the proteasome lid subunit, Rpn11 that exhibits accumulated levels of Cullin1-Rub1 conjugates, a characteristic phenotype of csn mutants. By dissecting between distinct phenotypes of rpn11 mutants, proteasome and mitochondria dysfunction, we were able to recognize the high reactive oxygen species (ROS) production during the transition of cells into mitochondrial respiration, as a checkpoint of Cullin1 rubylation in a reversible manner. Thus, the study adds the rubylation cascade to the list of cellular pathways regulated by redox homeostasis
Parallel Evolution of Quasi-separatrix Layers and Active Region Upflows
Persistent plasma upflows were observed with Hinode's EUV Imaging
Spectrometer (EIS) at the edges of active region (AR) 10978 as it crossed the
solar disk. We analyze the evolution of the photospheric magnetic and velocity
fields of the AR, model its coronal magnetic field, and compute the location of
magnetic null-points and quasi-sepratrix layers (QSLs) searching for the origin
of EIS upflows. Magnetic reconnection at the computed null points cannot
explain all of the observed EIS upflow regions. However, EIS upflows and QSLs
are found to evolve in parallel, both temporarily and spatially. Sections of
two sets of QSLs, called outer and inner, are found associated to EIS upflow
streams having different characteristics. The reconnection process in the outer
QSLs is forced by a large-scale photospheric flow pattern which is present in
the AR for several days. We propose a scenario in which upflows are observed
provided a large enough asymmetry in plasma pressure exists between the
pre-reconnection loops and for as long as a photospheric forcing is at work. A
similar mechanism operates in the inner QSLs, in this case, it is forced by the
emergence and evolution of the bipoles between the two main AR polarities. Our
findings provide strong support to the results from previous individual case
studies investigating the role of magnetic reconnection at QSLs as the origin
of the upflowing plasma. Furthermore, we propose that persistent reconnection
along QSLs does not only drive the EIS upflows, but it is also responsible for
a continuous metric radio noise-storm observed in AR 10978 along its disk
transit by the Nan\c{c}ay Radio Heliograph.Comment: 29 pages, 10 figure
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