Reputational Externality and Self-Regulation

Professional associations and other producer groups often complain that their reputation is damaged by other groups providing a similar but lower-quality service and that the latter should be regulated. We examine the conditions under which a common regulatory regime can induce Pareto-improvements by creating a common reputation for quality among heterogeneous producers, when the regulator cannot commit to a given quality. A common reputation can be created only if the groups are not too different and if marginal cost is declining. High cost groups and small groups benefit most from forming a common regime

Collective Reputation, Professional Regulation and Franchising

Collective reputation and its associated free-rider problem have been invoked to justify state licensing of professions and to explain the incidence of franchising. We examine the conditions under which it is possible to create a Pareto-improving collective reputation among groups of heterogeneous producers. If the regulator or franchisor cannot credibly commit to high quality then a common reputation can be created only if the groups are not too different and if marginal cost is declining. High cost groups benefit most from forming a common regime

Acute lung injury outside the ICU: a significant problem

The incidence of acute lung injury (ALI) is influenced by nature of the underlying clinical condition. The frequency with which ALI is likely to be encountered by those practicing outside the intensive care unit (ICU) setting is largely unknown. Data from the paper under discussion [1] indicates that ALI is seen relatively frequently in general wards and can be managed there until death or recovery. In patients with predisposing illnesses directly involving the lung, progression to ALI can be rapid

The promise of next generation colloids

The aim of perioperative haemodilution is to reduce loss of red blood cells during elective surgery. The oncotic and molecular characteristics of the various plasma substitutes employed determine how effectively normovolaemia is maintained, and their non-oncotic effects include alterations in microvascular perfusion. In the previous issue of Critical Care, Martini and colleagues assessed the effects of haemodilution with either polyethylene glycol (PEG)ylated albumin or a commercially available hydroxyethyl starch-based colloid in a hamster haemorrhage model. PEGylated albumin was superior to hydroxyethyl starch, as reflected by survival, haemodynamic parameters and assessment of the microcirculation using intravital microscopy

Bench-to-bedside review: Sepsis, severe sepsis and septic shock – does the nature of the infecting organism matter?

International guidelines concerning the management of patients with sepsis, septic shock and multiple organ failure make no reference to the nature of the infecting organism. Indeed, most clinical signs of sepsis are nonspecific. In contrast, in vitro data suggest that there are mechanistic differences between bacterial, viral and fungal sepsis, and imply that pathogenetic differences may exist between subclasses such as Gram-negative and Gram-positive bacteria. These differences are reflected in different cytokine profiles and mortality rates associated with Gram-positive and Gram-negative sepsis in humans. They also suggest that putative anti-mediator therapies may act differently according to the nature of an infecting organism. Data from some clinical trials conducted in severe sepsis support this hypothesis. It is likely that potential new therapies targeting, for example, Toll-like receptor pathways will require knowledge of the infecting organism. The advent of new technologies that accelerate the identification of infectious agents and their antimicrobial sensitivities may allow better tailored anti-mediator therapies and administration of antibiotics with narrow spectra and known efficacy

Bench-to-bedside review: Inhaled nitric oxide therapy in adults

Nitric oxide (NO) is an endogenous mediator of vascular tone and host defence. Inhaled nitric oxide (iNO) results in preferential pulmonary vasodilatation and lowers pulmonary vascular resistance. The route of administration delivers NO selectively to ventilated lung units so that its effect augments that of hypoxic pulmonary vasoconstriction and improves oxygenation. This 'Bench-to-bedside' review focuses on the mechanisms of action of iNO and its clinical applications, with emphasis on acute lung injury and the acute respiratory distress syndrome. Developments in our understanding of the cellular and molecular actions of NO may help to explain the hitherto disappointing results of randomised controlled trials of iNO

Magnetic anisotropy of the noncollinear antiferromagnet IrMn3

The magnetic anisotropy of antiferromagnets plays a crucial role in stabilizing the magnetization of many spintronic devices. In noncollinear antiferromagnets such as IrMn, the symmetry and temperature dependence of the effective anisotropy are poorly understood. Theoretical calculations and experimental measurements of the effective anisotropy constant for IrMn differ by two orders of magnitude, while the symmetry has been inferred as uniaxial in contradiction to the assumed relationship between crystallographic symmetry and temperature dependence of the anisotropy from the Callen-Callen law. In this Rapid Communication, we determine the effective anisotropy energy surface of L12-IrMn3 using an atomistic spin model and constrained Monte Carlo simulations. We find a unique cubiclike symmetry of the anisotropy not seen in ferromagnets and that metastable spin structures lower the overall energy barrier to a tenth of that estimated from simple geometrical considerations, removing the discrepancy between experiment and theory. The temperature scaling of the anisotropy energy barrier shows an exponent of 3.92, close to a uniaxial exponent of 3. Our results demonstrate the importance of noncollinear spin states on the thermal stability of antiferromagnets with consequences for the practical application of antiferromagnets in devices operating at elevated temperatures

Transformations in DOC along a source to sea continuum; impacts of photo-degradation, biological processes and mixing

Peatlands export significant amounts of dissolved organic carbon (DOC) to freshwaters, but the quantity of DOC reaching marine environments is typically less than the input to the fluvial system due to processing within the water column. Key removal processes include photo-chemical degradation, and heterotrophic bacterial respiration. In this study we examined these processes using 14C-labelled DOC to quantify the extent of DOC breakdown and to determine its fate following irradiation under controlled laboratory conditions. We examined the influence of microbial processes occurring within the water column, the potential role of stream-bed biofilms, and the possible modifying effects of downstream mixing, as DOC in water from the peatland encounters runoff from upland mineral soils (“Mountain”), nutrient-rich runoff from agricultural soils, and seawater in an estuary. Our results demonstrated conservative mixing of DOC from Peatland and Mountain waters but interactive effects when Peatland water was mixed with Agricultural and Estuary waters and exposed to solar radiation. The mixing of Peatland and Agricultural waters led to net DOC production, suggesting that DOC was only partially degraded by solar radiation and that the products of this might have fuelled autotrophic microbial growth in the samples. The mixing of Peatland water with saline estuary water resulted in net DOC loss following irradiation, suggesting a role for sunlight in enhancing the flocculation of DOC to particulate organic carbon (POC) in saline environments

The Bolocam Galactic Plane Survey. XIV. Physical Properties of Massive Starless and Star Forming Clumps

We sort $4683$ molecular clouds between $10^\circ< \ell <65^\circ$ from the Bolocam Galactic Plane Survey based on observational diagnostics of star formation activity: compact $70$ $\mu{\rm m}$ sources, mid-IR color-selected YSOs, ${\rm H_2O}$ and ${\rm CH_3OH}$ masers, and UCHII regions. We also present a combined ${\rm NH_3}$-derived gas kinetic temperature and ${\rm H_2O}$ maser catalog for $1788$ clumps from our own GBT 100m observations and from the literature. We identify a subsample of $2223$ ($47.5\%$) starless clump candidates, the largest and most robust sample identified from a blind survey to date. Distributions of flux density, flux concentration, solid angle, kinetic temperature, column density, radius, and mass show strong ($>1$ dex) progressions when sorted by star formation indicator. The median starless clump candidate is marginally sub-virial ($\alpha \sim 0.7$) with $>75\%$ of clumps with known distance being gravitationally bound ($\alpha < 2$). These samples show a statistically significant increase in the median clump mass of $\Delta M \sim 170-370$ M$_\odot$ from the starless candidates to clumps associated with protostars. This trend could be due to (i) mass growth of the clumps at $\dot{M}\sim200-440$ Msun Myr$^{-1}$ for an average free-fall $0.8$ Myr time-scale, (ii) a systematic factor of two increase in dust opacity from starless to protostellar phases, (iii) and/or a variation in the ratio of starless to protostellar clump lifetime that scales as $\sim M^{-0.4}$. By comparing to the observed number of ${\rm CH_3OH}$ maser containing clumps we estimate the phase-lifetime of massive ($M>10^3$ M$_\odot$) starless clumps to be $0.37 \pm 0.08 \ {\rm Myr} \ (M/10^3 \ {\rm M}_\odot)^{-1}$; the majority ($M<450$ M$_\odot$) have phase-lifetimes longer than their average free-fall time.Comment: Accepted for publication in ApJ; 33 pages; 22 figures; 7 table