1,815 research outputs found
Air ambulance outcome measures using Institutes of Medicine and Donabedian quality frameworks: protocol for a systematic scoping review
Background: Dedicated air ambulance services provide a vital link for critically ill and injured patients to higherlevels of care. The recent developments of pre-hospital and retrieval medicine create an opportunity for airambulance providers and policy-makers to utilize a dashboard of quality performance measures to assess serviceperformance. The objective of this scoping systematic review will be to identify and evaluate the range of airambulance outcome measures reported in the literature and help to construct a quality dashboard based on ahealthcare quality framework.
Methods: We will search PubMed, MEDLINE, CINAHL, Scopus, and Cochrane Database of Systematic Reviews (fromJanuary 2001 onwards). Complementary searches will be conducted in selected relevant journals. We will includesystematic reviews and observational studies (cohort, cross-sectional, interrupted time series) in critically ill orinjured patients published in English and focusing on air ambulance delivery and quality measures. Two reviewerswill independently screen all citations, full-text articles, and abstract data. The study methodological quality (or bias)will be appraised using appropriate tools. Analysis of the characteristics associated with outcome measure will bemapped and described according to the proposed healthcare quality framework.
Discussion: This review will contribute to the development of an air ambulance quality dashboard designed tocombine multiple quality frameworks. Our findings will provide a basis for helping decision-making in healthplanning and policy
Force distributions in a triangular lattice of rigid bars
We study the uniformly weighted ensemble of force balanced configurations on
a triangular network of nontensile contact forces. For periodic boundary
conditions corresponding to isotropic compressive stress, we find that the
probability distribution for single-contact forces decays faster than
exponentially. This super-exponential decay persists in lattices diluted to the
rigidity percolation threshold. On the other hand, for anisotropic imposed
stresses, a broader tail emerges in the force distribution, becoming a pure
exponential in the limit of infinite lattice size and infinitely strong
anisotropy.Comment: 11 pages, 17 figures Minor text revisions; added references and
acknowledgmen
Insulator-to-metal transition in sulfur-doped silicon
We observe an insulator-to-metal (I-M) transition in crystalline silicon
doped with sulfur to non- equilibrium concentrations using ion implantation
followed by pulsed laser melting and rapid resolidification. This I-M
transition is due to a dopant known to produce only deep levels at equilibrium
concentrations. Temperature-dependent conductivity and Hall effect measurements
for temperatures T > 1.7 K both indicate that a transition from insulating to
metallic conduction occurs at a sulfur concentration between 1.8 and 4.3 x
10^20 cm-3. Conduction in insulating samples is consistent with variable range
hopping with a Coulomb gap. The capacity for deep states to effect metallic
conduction by delocalization is the only known route to bulk intermediate band
photovoltaics in silicon.Comment: Submission formatting; 4 journal pages equivalen
Coherence properties of an atom laser
We study the coherence properties of an atom laser, which operates by
extracting atoms from a gaseous Bose-Einstein condensate via a two-photon Raman
process, by analyzing a recent experiment. We obtain good agreement with the
experimental data by solving the time-dependent Gross-Pitaevskii equation in
three dimensions both numerically and with a Thomas-Fermi model. The coherence
length is strongly affected by the space-dependent phase developed by the
condensate when the trapping potential is turned off.Comment: 11 pages, 2 Postscript figure
Excitation spectrum and instability of a two-species Bose-Einstein condensate
We numerically calculate the density profile and excitation spectrum of a
two-species Bose-Einstein condensate for the parameters of recent experiments.
We find that the ground state density profile of this system becomes unstable
in certain parameter regimes, which leads to a phase transition to a new stable
state. This state displays spontaneously broken cylindrical symmetry. This
behavior is reflected in the excitation spectrum: as we approach the phase
transition point, the lowest excitation frequency goes to zero, indicating the
onset of instability in the density profile. Following the phase transition,
this frequency rises again.Comment: 8 pages, 5 figures, uses REVTe
Inhibition of APE1/Ref-1 redox activity rescues human retinal pigment epithelial cells from oxidative stress and reduces choroidal neovascularization
The effectiveness of current treatment for age related macular degeneration (AMD) by targeting one molecule is limited due to its multifactorial nature and heterogeneous pathologies. Treatment strategy to target multiple signaling pathways or pathological components in AMD pathogenesis is under investigation for better clinical outcome. Inhibition of the redox function of apurinic endonuclease 1/redox factor-1 (APE1) was found to suppress endothelial angiogenesis and promote neuronal cell recovery, thereby may serve as a potential treatment for AMD. In the current study, we for the first time have found that a specific inhibitor of APE1 redox function by a small molecule compound E3330 regulates retinal pigment epithelium (RPEs) cell response to oxidative stress. E3330 significantly blocked sub-lethal doses of oxidized low density lipoprotein (oxLDL) induced proliferation decline and senescence advancement of RPEs. At the same time, E3330 remarkably decreased the accumulation of intracellular reactive oxygen species (ROS) and down-regulated the productions of monocyte chemoattractant protein-1 (MCP-1) and vascular endothelial growth factor (VEGF), as well as attenuated the level of nuclear factor-κB (NF-κB) p65 in RPEs. A panel of stress and toxicity responsive transcription factors that were significantly upregulated by oxLDL was restored by E3330, including Nrf2/Nrf1, p53, NF-κB, HIF1, CBF/NF-Y/YY1, and MTF-1. Further, a single intravitreal injection of E3330 effectively reduced the progression of laser-induced choroidal neovascularization (CNV) in mouse eyes. These data revealed that E3330 effectively rescued RPEs from oxidative stress induced senescence and dysfunctions in multiple aspects in vitro, and attenuated laser-induced damages to RPE–Bruch׳s membrane complex in vivo. Together with its previously established anti-angiogenic and neuroprotection benefits, E3330 is implicated for potential use for AMD treatment
Accountability, Strategy, and International Non-Governmental Organizations
Increased prominence and greater influence expose international non-governmental development and environmental organizations (INGOs) to increased demands for accountability from a wide variety of stakeholdersdonors, beneficiaries, staffs, and partners among others. This paper focuses on developing the concept of INGO accountability, first as an abstract concept and then as a strategic idea with very different implications for different INGO strategies. We examine those implications for INGOs that emphasize service delivery, capacity-building, and policy influence. We propose that INGOs committed to service delivery may owe more accountability to donors and service regulators; capacity-building INGOs may be particularly obligated to clients whose capacities are being enhanced; and policy influence INGOs may be especially accountable to political constituencies and to influence targets. INGOs that are expanding their activities to include new initiatives may need to reorganize their accountability systems to implement their strategies effectively. This publication is Hauser Center Working Paper No. 7. The Hauser Center Working Paper Series was launched during the summer of 2000. The Series enables the Hauser Center to share with a broad audience important works-in-progress written by Hauser Center scholars and researchers
Collective excitations of Bose-Einstein condensed gases at finite temperatures
We have applied the Popov version of the Hartree-Fock-Bogoliubov (HFB)
approximation to calculate the finite-temperature excitation spectrum of a
Bose-Einstein condensate (BEC) of Rb atoms. For lower values of the
temperature, we find excellent agreement with recently-published experimental
data for the JILA TOP trap. In contrast to recent comparison of the results of
HFB--Popov theory with experimental condensate fractions and specific heats,
there is disagreement of the theoretical and recent experimental results near
the BEC phase transition temperature.Comment: 4 pages, Latex, with 4 figures. More info at
http://amo.phy.gasou.edu/bec.htm
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