Monopolists and Viscous Demand

We characterize the optimal dynamic price policy of a monopolist who faces "viscous" demand for its services. Demand is viscous if it adjusts relatively slowly to price changes. We show that with the optimal policy the monopolist stops short of achieving 100% market penetration, even when all of the consumers have the same long-run willingness to pay for the service. Furthermore, for certain parameter values in the model, the price policy requires rapid oscillations of the price path.Information Systems Working Papers Serie

Communication in networks with hierarchical branching

We present a simple model of communication in networks with hierarchical branching. We analyze the behavior of the model from the viewpoint of critical systems under different situations. For certain values of the parameters, a continuous phase transition between a sparse and a congested regime is observed and accurately described by an order parameter and the power spectra. At the critical point the behavior of the model is totally independent of the number of hierarchical levels. Also scaling properties are observed when the size of the system varies. The presence of noise in the communication is shown to break the transition. Despite the simplicity of the model, the analytical results are a useful guide to forecast the main features of real networks.Comment: 4 pages, 3 figures. Final version accepted in PR

Optimal network topologies for local search with congestion

The problem of searchability in decentralized complex networks is of great importance in computer science, economy and sociology. We present a formalism that is able to cope simultaneously with the problem of search and the congestion effects that arise when parallel searches are performed, and obtain expressions for the average search cost--written in terms of the search algorithm and the topological properties of the network--both in presence and abscence of congestion. This formalism is used to obtain optimal network structures for a system using a local search algorithm. It is found that only two classes of networks can be optimal: star-like configurations, when the number of parallel searches is small, and homogeneous-isotropic configurations, when the number of parallel searches is large.Comment: 4 pages. Final version accepted in PR

Fashion and passion: marketing sex to women

Against a backdrop of a ‘pornographication’ of mainstream media and the emergence of a more heavily sexualized culture, women are increasingly targeted as sexual consumers. In the UK, the success of TV shows like Sex and the City and the ‘fashion ‘n’ passion’ of sex emporia like Ann Summers suggests that late twentieth century discourses which foregrounded female pleasure have crystallised in a new form of sexual address to women. This article examines how sex products are being marketed for female consumers, focussing on the websites of sex businesses such as Myla, Babes n Horny, Beecourse, tabooboo and Ann Summers. It asks how a variety of existing discourses – of fashion, consumerism, bodily pleasure and sexuality - are drawn on in the construction of this new market, how they negotiate the dangers and pleasures of sexuality for women, and what they show about the construction of ‘new’ female sexualities.</p

Effect of nocturnal Temperature-controlled Laminar Airflow on the reduction of severe exacerbations in patients with severe allergic asthma: a meta-analysis

Background: Allergen avoidance is important in allergic asthma management. Nocturnal treatment with Temperature-controlled Laminar Airflow (TLA) has been shown to provide a significant reduction in the exposure to allergens in the breathing zone, leading to a long-term reduction in airway inflammation and improvement in Quality of life (QoL). Allergic asthma patients symptomatic on Global Initiative for Asthma (GINA) step 4/5 were found to benefit the most as measured by Asthma Quality of Life Questionnaire (AQLQ). However, the effect of TLA on severe asthma exacerbations is uncertain and therefore a meta-analysis was performed. Methods: Patients with severe allergic asthma (GINA 4/5) were extracted from two 1-year randomised, double-blind, placebo-controlled trials conducted with TLA. A meta-analysis of the effect on severe exacerbations was performed by negative binomial regression in a sequential manner, defined by baseline markers of asthma control (symptoms and QoL scores). Results: The pooled dataset included 364patients. Patients with more symptoms at baseline (ACT3; N=179), had a significant mean 41% reduction in severe exacerbations (RR=0.59 (0.38-0.90); p=0.015) in favour of TLA. Higher ACQ7 cut-points of 3.5-4.5 resulted in significant reductions of 48-59%.More uncontrolled patients based on AQLQ total and symptom domains ≤3.0 at baseline also showed a significant reduction in severe exacerbations for TLA vs. placebo ((47% (p=0.037) and 53% (p=0.011), respectively). The meta-analysis also confirmed a significant difference in AQLQ-responders ((Minimal Clinically Important Difference)≥0.5; 74% vs. 43%, p=0.04). Conclusion: This meta-analysis of individual patient data shows a beneficial effect on severe exacerbations and quality of life for TLA over placebo in more symptomatic patients with severe allergic asthma. These outcomes support the national management recommendations for patients with symptomatic severe allergic asthma. The actual effect of TLA on severe exacerbations should be confirmed in a prospective study with larger numbers of patients

Museu Militar de Bragança: fundação, práticas museológicas

O objecto de estudo decidido para este trabalho centra-se na reflexão sobre o Museu Militar de Bragança hoje, e as suas potencialidades enquanto gerador de desenvolvimento social. Para fazer esta reflexão consideramos pertinente a pesquisa histórica do museu, desde a sua fundação, atendendo à função e os objectivos propostos inicialmente pela instituição, bem como aos procedimentos museológicos actualmente observados. O museu militar de Bragança surge no primeiro quartel do século XX como um espaço de salvaguarda das memórias dos feitos bélicos das forças militares sedeadas em Bragança. Após a erradicação da última unidade militar de Bragança, em 1958, o museu é temporariamente encerrado e trasladado o acervo para o Museu Militar de Lisboa. Já na década de 80 do século XX o museu volta a ser instalado no local de origem, a torre de menagem do castelo, e impõe-se como espaço \ memória das vivências militares da cidade. No entanto, cremos que, para que o Museu Militar potencie as suas ferramentas enquanto gerador de desenvolvimento social, seria desejável consumar alguns procedimentos museológicos, actualmente já impostos na Lei Quadro dos museus. Neste sentido, na segunda parte do presente trabalho propomo-nos estabelecer um plano geral de práticas museológicas adaptado ao caso concreto do Museu Militar de Bragança. O presente trabalho aspira assim: a caracterizar sucintamente o conceito actual de Museu; a descrever o edifício onde está instalado o Museu Militar de Bragança, que constitui parte integrante da sua valência enquanto gerador de desenvolvimento local; a pesquisar o processo de fundação do museu, os seus objectivos e funções enquanto parte integrante de um maior complexo militar como era o quartel. (...