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

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. Please click Additional Files below to see the full abstract