Manipulable Congestion Tolls

The recent literature on congestion pricing with large agents contains a remarkable inconsistency: though agents are large enough to recognize self-imposed congestion and exert market power over prices, they do not take into account the impact of their own actions on the magnitude of congestion tolls. When large agents are confronted with tolls derived under this parametric assumption but understand the rule used to generate them, the toll system will no longer guide the market to the social optimum. To address this problem, the present paper derives alternate, manipulable toll rules, which are designed to achieve the social optimum when agents anticipate the full impact of their actions on toll liabilities.Pigouvian taxes; Congestion tolls

Manipulable Congestion Tolls

The recent literature on congestion pricing with large agents contains a remarkable inconsistency: though agents are large enough to recognize self-imposed congestion and exert market power over prices, they do not take into account the impact of their own actions on the magnitude of congestion tolls. When large agents are confronted with tolls derived under this parametric assumption but understand the rule used to generate them, the toll system will no longer guide the market to the social optimum. To address this problem, the present paper derives alternate, manipulable toll rules, which are designed to achieve the social optimum when agents anticipate the full impact of their actions on toll liabilities

Pricing, Capacity Choice and Financing in Transportation Networks

This paper explores the inerrelations between pricing, capacity choice and financing in transportation networks. It builds on the famous Mohring-Harwitz result on self-financing of optimally designed roads under optimal congestion pricing, and specifically asks the following questions: (1) to what extent does the result apply under conditions of second-best pricing?; (2) which are the implications of having uncongested (e.g. rural) roads in a network?; and (3) what is the role of fixed (annual) taxes in this context? The paper develops a small network model, with endogenous car-ownership, in order to study these questions both from an analytical and a numerical viewpoint.

Treatment of Gram-Negative Septic Shock with Human IgG Antibody to Escherichia coli J5: A Prospective, Double-Blind, Randomized Trial

In a randomized, double-blind, multicenter trial we compared the efficacy of a preparation of human IgG antibody to Escherichia coli 15 (J5-IVIG) with that of a standard IgG preparation (IVIG) for the treatment of gram-negative septic shock. At study entry, patients received a single intravenous dose of 200 mg/kg of body weight (maximal dose, 12 g) of either J5-IVIG or IVIG. Of the 100 patients randomized, 71 (30 receiving J5-IVIG and 41 receiving IVIG) had a documented gram-negative infection. Mortality from gram-negative septic shock was 50% (15 of 30) in J5-IVIG recipients and 49% (20 of 41) in IVIG recipients. In addition, treatment with J5-IVIG did not reduce the number of systemic complications of shock and did not delay the occurrence of death due to septic shock. Thus we conclude that 15-IVIG was not superior to IVIG in reducing mortality or in reversing gram-negative septic shoc

Enterobacter cloacae Outbreak and Emergence of Quinolone Resistance Gene in Dutch Hospital

Plasmid-mediated qnrA1 is an emerging resistance trait

Evolution in Quantum Leaps: Multiple Combinatorial Transfers of HPI and Other Genetic Modules in Enterobacteriaceae

Horizontal gene transfer is a key step in the evolution of Enterobacteriaceae. By acquiring virulence determinants of foreign origin, commensals can evolve into pathogens. In Enterobacteriaceae, horizontal transfer of these virulence determinants is largely dependent on transfer by plasmids, phages, genomic islands (GIs) and genomic modules (GMs). The High Pathogenicity Island (HPI) is a GI encoding virulence genes that can be transferred between different Enterobacteriaceae. We investigated the HPI because it was present in an Enterobacter hormaechei outbreak strain (EHOS). Genome sequence analysis showed that the EHOS contained an integration site for mobile elements and harbored two GIs and three putative GMs, including a new variant of the HPI (HPI-ICEEh1). We demonstrate, for the first time, that combinatorial transfers of GIs and GMs between Enterobacter cloacae complex isolates must have occurred. Furthermore, the excision and circularization of several combinations of the GIs and GMs was demonstrated. Because of its flexibility, the multiple integration site of mobile DNA can be considered an integration hotspot (IHS) that increases the genomic plasticity of the bacterium. Multiple combinatorial transfers of diverse combinations of the HPI and other genomic elements among Enterobacteriaceae may accelerate the generation of new pathogenic strains

Mannose binding lectin plays a crucial role in innate immunity against yeast by enhanced complement activation and enhanced uptake of polymorphonuclear cells

<p>Abstract</p> <p>Background</p> <p>Mannose binding lectin (MBL) is an important host defence protein against opportunistic fungal pathogens. This carbohydrate-binding protein, an opsonin and lectin pathway activator, binds through multiple lectin domains to the repeating sugar arrays displayed on the surface of a wide range of clinically relevant microbial species. We investigated the contribution of MBL to antifungal innate immunity towards <it>C. parapsilosis in vitro</it>.</p> <p>Results</p> <p>High avidity binding was observed between MBL and <it>C. albicans </it>and <it>C. parapsilosis</it>. Addition of MBL to MBL deficient serum increased the deposition of C4 and C3b and enhanced the uptake of <it>C. albicans</it>, <it>C. parapsilosis </it>and acapsular <it>C. neoformans </it>by polymorphonuclear cells (PMNs). Compared to other microorganisms, such as <it>Escherichia coli</it>, <it>Staphylococcus aureus </it>and <it>Cryptococcus neoformans</it>, <it>C. parapsilosis </it>and <it>Candida albicans </it>were potent activators of the lectin pathway.</p> <p>Conclusion</p> <p>Our results suggest that MBL plays a crucial role in the innate immunity against infections caused by yeast by increasing uptake by PMN.</p

Peritoneal defense in continuous ambulatory versus continuous cyclic peritoneal dialysis

Peritoneal defense in continuous ambulatory peritoneal dialysis versus continuous cyclic peritoneal dialysis. Several centers have reported a lower rate of peritonitis among adult patients on continuous cyclic peritoneal dialysis (CCPD) as compared to those undergoing continuous ambulatory peritoneal dialysis (CAPD). Preliminary results of our ongoing prospective randomized study comparing CAPD-Y with CCPD also suggest a lower peritonitis incidence among CCPD-treated patients. To investigate whether the two dialysis regimens could result in differences in local host defense, we studied peritoneal macrophage (PMO) function and effluent opsonic activity in eight patients established on CAPD-Y matched with eight chronic CCPD patients. Since short and long dwell times are inherent to both dialysis modalities, and we previously found that dwell time has an impact on PMO function and effluent opsonic activity, patients were studied after both a short (4hr) and a long (15hr) dwell time. In both patient groups PMO phagocytic capacity increased significantly with dwell time (39 ± 3.3% at 4hr vs. 58 ± 4.2% at 15hr in CAPD patients, and 40 ± 3.9 vs. 72 ± 3.3% in CCPD patients; P < 0.01), as did PMO peak chemiluminescence response (31 ± 4.9 vs. 77 ± 7.2 counts · min-1/104 cells in CAPD, and 22 ± 3.9 vs. 109 ± 21.2 counts · min-1/104 cells in CCPD; P < 0.01) and effluent opsonic activity (41 ± 7.6 vs. 73 ± 5.8% in CAPD and 39 ± 6.2 vs. 70 ± 5.9% in CCPD; P < 0.01). However, no significant difference was found in either variable between CAPD and CCPD patients when dwell times were equal. In conclusion, no differences were observed in PMO function or effluent opsonic activity between matched CAPD-Y and CCPD patients when dwell times were equal. In both patient groups prolongation of dwell time enhanced PMO function as well as effluent opsonic activity, thereby providing a better host defense. The improvement in peritoneal defenses may, in part, be responsible for the lower peritonitis incidence observed among CCPD-treated patients