835 research outputs found
Performance of Trust-Based Governance
Trust is crucial for the success of interorganizational relationships, yet we lack a clear
understanding of when trust-based governance is likely to succeed or fail. This paper
explores that topic via a closed-form and a computational analysis of a formal model
based on the well-known trust game. We say that trust-based governance performs
better in situations where it results in a willingness to be vulnerable with trustworthy
others and an unwillingness to be vulnerable with untrustworthy others. We find that
trust-based governance performs better in situations in which (a) trustworthy and
untrustworthy partners exhibit markedly different behavior (high behavioral risk) or
(b) the organization is willing to be vulnerable despite doubts concerning the partner’s
trustworthiness (low trust threshold)
Elliptical instability of a rapidly rotating, strongly stratified fluid
The elliptical instability of a rotating stratified fluid is examined in the
regime of small Rossby number and order-one Burger number corresponding to
rapid rotation and strong stratification. The Floquet problem describing the
linear growth of disturbances to an unbounded, uniform-vorticity elliptical
flow is solved using exponential asymptotics. The results demonstrate that the
flow is unstable for arbitrarily strong rotation and stratification; in
particular, both cyclonic and anticyclonic flows are unstable. The instability
is weak, however, with growth rates that are exponentially small in the Rossby
number. The analytic expression obtained for the growth rate elucidates its
dependence on the Burger number and on the eccentricity of the elliptical flow.
It explains in particular the weakness of the instability of cyclonic flows,
with growth rates that are only a small fraction of those obtained for the
corresponding anticyclonic flows. The asymptotic results are confirmed by
numerical solutions of Floquet problem.Comment: 17 page
Acute and life-threatening remifentanil overdose resulting from the misuse of a syringe pump.
In the perioperative setting, syringe pumps are frequently used. They guarantee constant plasma levels of hypnotics, opioids, cardiovascular medication, insulin or other drugs. We present a case in which an inadvertent rapid intravenous injection of 2 mg remifentanil occurred due to the misuse of a syringe pum
Tinnitus: network pathophysiology-network pharmacology
Tinnitus, the phantom perception of sound, is a prevalent disorder. One in 10 adults has clinically significant subjective tinnitus, and for one in 100, tinnitus severely affects their quality of life. Despite the significant unmet clinical need for a safe and effective drug targeting tinnitus relief, there is currently not a single Food and Drug Administration (FDA)-approved drug on the market. The search for drugs that target tinnitus is hampered by the lack of a deep knowledge of the underlying neural substrates of this pathology. Recent studies are increasingly demonstrating that, as described for other central nervous system (CNS) disorders, tinnitus is a pathology of brain networks. The application of graph theoretical analysis to brain networks has recently provided new information concerning their topology, their robustness and their vulnerability to attacks. Moreover, the philosophy behind drug design and pharmacotherapy in CNS pathologies is changing from that of “magic bullets” that target individual chemoreceptors or “disease-causing genes” into that of “magic shotguns,” “promiscuous” or “dirty drugs” that target “disease-causing networks,” also known as network pharmacology. In the present work we provide some insight into how this knowledge could be applied to tinnitus pathophysiology and pharmacotherapy
Acute and life-threatening remifentanil overdose resulting from the misuse of a syringe pump.
Acute and life-threatening remifentanil overdose resulting from the misuse of a syringe pump.
Effects of Spatially Nonuniform Gain on Lasing Modes in Weakly Scattering Random Systems
A study on the effects of optical gain nonuniformly distributed in
one-dimensional random systems is presented. It is demonstrated numerically
that even without gain saturation and mode competition, the spatial
nonuniformity of gain can cause dramatic and complicated changes to lasing
modes. Lasing modes are decomposed in terms of the quasi modes of the passive
system to monitor the changes. As the gain distribution changes gradually from
uniform to nonuniform, the amount of mode mixing increases. Furthermore, we
investigate new lasing modes created by nonuniform gain distributions. We find
that new lasing modes may disappear together with existing lasing modes,
thereby causing fluctuations in the local density of lasing states.Comment: 26 pages, 10 figures (quality reduced for arXiv
Scattering of swell by currents
The refraction of surface gravity waves by currents leads to spatial
modulations in the wave field and, in particular, in the significant wave
height. We examine this phenomenon in the case of waves scattered by a
localised current feature, assuming (i) the smallness of the ratio between
current velocity and wave group speed, and (ii) a swell-like, highly
directional wave spectrum.
We apply matched asymptotics to the equation governing the conservation of
wave action in the four-dimensional position--wavenumber space. The resulting
explicit formulas show that the modulations in wave action and significant wave
height past the localised current are controlled by the vorticity of the
current integrated along the primary direction of the swell.
We assess the asymptotic predictions against numerical simulations using
WAVEWATCH III for a Gaussian vortex. We also consider vortex dipoles to
demonstrate the possibility of `vortex cloaking' whereby certain currents have
(asymptotically) no impact on the significant wave height. We discuss the role
of the ratio of the two small parameters characterising assumptions (i) and
(ii) above and show that caustics are only significant for unrealistically
large values of this ratio, corresponding to unrealistically narrow directional
spectra
Salinity gradient energy: Assessment of pressure retarded osmosis and osmotic heat engines for energy generation from low-grade heat sources
Development of clean energy technologies that maximize efficiency and minimize resource consumption is a necessary component for a clean and secure energy future. The osmotic heat engine (OHE) is a closed-loop, membrane based process that utilizes low-grade heat and salinity-gradient energy between two streams for electrical energy generation. The OHE couples pressure retarded osmosis (PRO), an osmotically driven membrane process, with membrane distillation (MD), a thermally driven membrane process. In PRO, water permeates via osmosis through a semi-permeable membrane from a low concentration feed stream into a higher concentration brine (draw solution). The permeate stream becomes pressurized on the high concentration side of the membrane and a mechanical device (e.g., turbine generator set) is used to convert the hydraulic pressure to electrical energy. The MD process utilizes low-grade heat to reconcentrate the diluted brine from the PRO process and to produce a deionized water stream; these streams are then resupplied to the PRO process in the OHE. High power-density (power generated per unit area of membrane) of the PRO membrane is essential to maximize the efficiency and minimize the capital and operating costs of the OHE. Likewise, high separation efficiency is needed in the MD process to effectively reconcentrate the diluted draw solution. Thus, robust PRO membranes that can support high pressure, have high water flux, low reverse salt flux, low structural parameter, and a good membrane support structure are essential. The MD process must also be able to withstand high operating temperatures (\u3e 60 ºC) and feed water concentrations, and have low pore wetting propensity. Additionally, the use of highly soluble ionic organic and inorganic draw solutions can increase PRO power densities while achieving high MD water fluxes, thus increasing efficiencies and decreasing costs of OHE.
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Static secondary ion mass spectrometry (S-SIMS) analysis of atmospheric plasma treated polypropylene films
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