Subadditivity and Contestability in the Postal Sector: Theory and Evidence

Several studies have been conducted to analyze whether a regulation of the postal sector as a monopoly is actually efficient by examining its cost structure. The authors detected significant scale economies only in the delivery function and hence demonstrated a necessity for competition in the upstream operations. The primary purpose of this paper is to summarize the basic conditions of natural monopoly theory and to review the approaches and results of the studies dealing with this topic. Despite the importance of contestability in this context, previous literature concentrates only on the subadditivity aspect. The existence of economies of scale does not inevitably justify a governmental maintenance of the monopoly if the market is contestable. In this respect, further research is needed in order to account for contestability.Postal Sector, Scale Economies, Subadditivity, Contestability

Dynamical Heterogeneities and Cooperative Motion in Smectic Liquid Crystals

Using simulations of hard rods in smectic-A states, we find non-gaussian diffusion and heterogeneous dynamics due to the equilibrium periodic smectic density profiles, which give rise to permanent barriers for layer-to-layer diffusion. This relaxation behavior is surprisingly similar to that of non-equilibrium supercooled liquids, although there the particles are trapped in transient (instead of permanent) cages. Interestingly, we also find stringlike clusters of up to 10 inter-layer rods exhibiting dynamic cooperativity in this equilibrium state.Comment: 10 pages, 4 figure

Brambilla et al. Reply to a Comment by J. Reinhardt et al. on "Probing the equilibrium dynamics of colloidal hard spheres above the mode-coupling glass transition"

G. Brambilla et al. Reply to a Comment by J. Reinhardt et al. questioning the existence of equilibrium dynamics above the critical volume fraction of colloidal hard spheres predicted by mode coupling theory.Comment: To appear in Phys. Rev. Lett. Reply to a Comment by J. Reinhardt et al. (see arXiv:1010.2891), which questions the existence of equilibrium dynamics above the critical volume fraction of glassy colloidal hard spheres predicted by mode coupling theor

Subdiffusion and intermittent dynamic fluctuations in the aging regime of concentrated hard spheres

We study the nonequilibrium aging dynamics in a system of quasi-hard spheres at large density by means of computer simulations. We find that, after a sudden quench to large density, the relaxation time initially increases exponentially with the age of the system. After a surprisingly large crossover time, the system enters the asymptotic aging regime characterized by a linear increase of the relaxation time with age. In this aging regime, single particle motion is strongly non-Fickian, with a mean-squared displacement increasing subdiffusively, associated to broad, non-Gaussian tails in the distribution of particle displacements. We find that the system ages through temporally intermittent relaxation events, and a detailed finite size analysis of these collective dynamic fluctuations reveals that these events are not spanning the entire system, but remain spatially localized.Comment: 11 pages; 10 fig

Testing for viral penetration of non-latex surgical and examination gloves: a comparison of three methods

ABSTRACTCurrently, there are no international standards based on microbiological methodology for testing the ability of medical examination or surgical gloves to prevent the passage of viruses. Three protocols for the direct examination of the viral barrier properties of non-latex gloves were compared with 1080 gloves (270 gloves from each of two surgical brands and two medical examination brands). In two of the methods, gloves were filled with and suspended in a nutrient broth solution, and bacteriophage ϕX174 was placed either inside or outside the glove, while the entire test vessel was agitated. Gloves tested using the third method were filled with a suspension of bacteriophage and allowed to rest in a vessel containing nutrient broth. Gloves were tested directly from the manufacturer's packaging, or after being punctured intentionally or subjected to a stress protocol. The passage of bacteriophage was detected with plaque assays. Significant differences in failure rates between glove brands were apparent only among gloves that had been subjected to the stress protocol. Overall, the two methods in which bacteriophage were placed inside the gloves provided more sensitivity than the method in which bacteriophage was spiked into broth outside the gloves. Thus the placement of bacteriophage inside test gloves (or the use of pressure across the glove barrier during testing), and the use of a standardised stress protocol, will improve significantly the ability of a glove test protocol to determine the relative quality of the barrier offered by medical examination and surgical gloves. Further research is needed to provide test methods that can incorporate reproducibly both the use of bacteriophage and simulated glove use in an industrial quality control setting

Real-world questions and concerns about disease-modifying antirheumatic drugs (DMARDs): A retrospective analysis of questions to a medicine call center

Background: Disease-modifying antirheumatic drugs (DMARDs) have transformed the treatment of numerous autoimmune and inflammatory diseases but their perceived risk of harm may be a barrier to use. Methods: In a retrospective mixed-methods study, we analysed conventional (c) and biologic (b) DMARDs-related calls and compared them with rest of calls (ROC) from consumers to an Australian national medicine call center operated by clinical pharmacists from September 2002 to June 2010. This includes the period where bDMARDs became available on the Pharmaceutical Benefits Scheme, the government-subsidized prescription medicines formulary. We compared caller and patient demographics, enquiry types and motivation to information-seek for both cDMARDs and bDMARDs with ROC, using a t-test for continuous data and a chi-square test for categorical data. We explored call narratives to identify common themes. Results: There were 1547 calls involving at least one DMARD. The top three cDMARD enquiry types were side effects (27.2%), interactions (21.9%), and risk versus benefit (11.7%). For bDMARDs, the most common queries involved availability and subsidized access (18%), mechanism and profile (15.8%), and side effects (15.1%). The main consumer motivations to information-seek were largely independent of medicines type and included: inadequate information (44%), wanting a second opinion (23.6%), concern about a worrying symptom (18.8%), conflicting information (6.9%), or information overload (2.3%). Question themes common to conventional and biological DMARDs were caller overemphasis on medication risk and the need for reassurance. Callers seeking information about bDMARDs generally overestimated effectiveness and focused their attention on availability, cost, storage, and medicine handling. Conclusion: Consumers have considerable uncertainty regarding DMARDs and may overemphasise risk. Patients cautiously assess the benefits and risks of their DMARDs but when new treatments emerge, they tend to overestimate their effectivenes

Exergy Analysis of Combined Cycles: Part 2-Analysis and Optimization of Two-Pressure Steam Bottoming Cycles

Results of a study for selecting the optimum parameters of a dual-pressure bottoming cycle as a function of the gas turbine Introduction Thermal optimization of steam bottoming cycles operating on gas turbine exhaust heat differs from that for directly fired boilers in that the heat supply is of relatively low grade. One purpose of this paper is to provide a basis for quantifying the improvements to cycle performance that can be brought about by adopting measures which reduce heat transfer irreversibility as well as variation of the design parameters or constraints. This basis is provided by the presentation of detailed exergy balances of steam cycles base

Bilateral Concurrent Benign Phyllodes Tumor in a 43-Year-Old Female: A Case Report.

Phyllodes tumor is considered a rare form of breast tissue neoplasm that presents as a rapidly growing painless mass. This neoplasm is classified as benign, borderline, or malignant and standard treatment consists of surgical excision with clear margins. The vast majority of reported cases have described the unilateral presentation of this tumor, making bilateral presentation a rare find. Our case describes a 43-year-old Hispanic woman with a history of fibroadenomas who was found to have concurrent benign bilateral phyllodes tumors