Intérêt public, intérêt privé et discrimination

Nous considérons un service à qualité variable dont chaque usager consomme au plus une unité. Les coûts de production, fixe et variable, ne dépendent pas de la qualité : améliorer, dans certaines limites, la qualité, n’augmente pas les coûts de production. Chaque usager cependant apprécie d’autant plus le service que celui-ci est de meilleure qualité : la propension à payer de l’usager est une fonction linéaire croissante de la qualité du service.Chaque usager est seul à connaître sa propre propension à payer, alors que la distribution des propensions est connue de tous, producteurs et consommateurs. Nous étudions comment et pourquoi, dans ces conditions, une discrimination par les prix et les qualités peut être pratiquée par les producteurs. Nous montrons qu’un monopole recherchant la maximisation de son profit ne pratiquera pas de discrimination; en revanche, dans un large champ de situation, il n’est possible d’atteindre un optimum de Pareto sous contraintes — informationnelle et financière — qu’en discriminant : le gain qu’apporte la discrimination en tant que mécanisme d’autosélection l’emporte sur le gaspillage qu’il y a à produire au même coût une qualité moindre.Nous reformulons enfin notre modèle pour élargir son domaine d’application à des questions telles que la tarification de l’accès à un réseau téléphonique, le marchandage dans un contexte d’achats répétés, etc.We consider a service whose quality is variable and from which every consumer consumes either one unit or nothing. Production costs, both fixed and variable, do not depend on quality: a higher quality service is no more costly to produce than a lower quality one. On the consumption side however, higher quality is preferred: a consumer's willingness-to-pay for one unit of the service is an increasing and linear function of the service quality.A consumer's willingness-to-pay is private information to him, whereas the corresponding distribution over all consumers is public information, hence known to the producers. In this setting we investigate why and how producers might use price and quality discrimination. We show that a profit-maximising monopolist will not discriminate, whereas it is often the case that reaching a constrained Pareto optimum will not be possible without some recourse—which we precisely define—to discrimination: the improvement in welfare thus brought by self-selection is worth some waste of quality.In the last section we reformulate our model in order to include in the analysis such topics as network access pricing, selling strategies when buying is repeated, etc

Intérêt public, intérêt privé et discrimination

We consider a service whose quality is variable and from which every consumer consumes either one unit or nothing. Production costs, both fixed and variable, do not depend on quality: a higher quality service is no more costly to produce than a lower quality one. On the consumption side however, higher quality is preferred: a consumer's willingness-to-pay for one unit of the service is an increasing and linear function of the service quality. Nous considérons un service à qualité variable dont chaque usager consomme au plus une unité. Les coûts de production, fixe et variable, ne dépendent pas de la qualité : améliorer, dans certaines limites, la qualité, n’augmente pas les coûts de production. Chaque usager cependant apprécie d’autant plus le service que celui-ci est de meilleure qualité : la propension à payer de l’usager est une fonction linéaire croissante de la qualité du service.

Transcriptomic analysis of the exit from dormancy of Aspergillus fumigatus conidia

<p>Abstract</p> <p>Background</p> <p>Establishment of aspergillosis is depending upon the exit from dormancy and germination of the conidia of <it>Aspergillus fumigatus </it>in the lung. To gain an understanding of the molecular mechanisms underlying the early steps of conidial germination, we undertook a transcriptomic analysis using macroarrays constructed with PCR fragments from > 3,000 genes (around one third of the annotated <it>A</it>. <it>fumigatus </it>genome).</p> <p>Results</p> <p>Major results of this analysis are the following: (i) conidia stored pre-packaged mRNAs transcripts (27% of genes have transcripts in the resting conidia; (ii) incubation at 37°C in a nutritive medium induced up- and down-regulation of genes: 19% of the total number of genes deposited on the array were up-regulated whereas 22% of the genes with pre-packaged mRNA in the resting conidia were down-regulated; (iii) most modifications were seen during the first 30 min of germination whereas very little modification of gene expression occurred during the following hour; (iv) one-year old conidia and one-week old conidia behaved similarly at transcriptional level.</p> <p>Conclusion</p> <p>Transcriptomic data indicate that the exit from dormancy is associated with a shift from a fermentative metabolism to a respiratory metabolism as well as a trend toward immediate protein synthesis.</p

Hygrothermal behaviour of hemp concrete; experimental evidences and modelling

This paper presents experimental hygrothermal data of an hemp concrete wall of dimensions 0.9×0.9×0.1 [m3]. The wall is instrumented with sensors to monitor temperature, relative humidity at the middle of the wall and incoming heat flows at the external surfaces. It is placed in a double climatic chamber that allows the regulation of temperature and relative humidity on each side of the wall, independently to each other. The experimental results leads to a clear identification of the coupling between the variation of the relative humidity inside the wall and its temperature. The validity of the commonly adopted assumptions for hygrothermal simulation are finally analyzed in the light of these experimental results. The material parameters used for the simulations are measured separately on decimetric samples of the same hemp concrete, which comes from the same mix and with the same apparent density

An Economic Comparison between Alternative Rice Farming Systems in Tanzania Using a Monte Carlo Simulation Approach

Tanzania is the second-largest producer of rice (Oryza sativa) in Eastern, Central, and Southern Africa after Madagascar. Unfortunately, the sector has been performing poorly due to many constraints, including poor agricultural practices and climate variability. In addressing the challenge, the government is making substantial investments to speed the agriculture transformation into a more modernized, commercial, and highly productive and profitable sector. Our objective was to apply a Monte Carlo simulation approach to assess the economic feasibility of alternative rice farming systems operating in Tanzania while considering risk analysis for decision-makers with different risk preferences to make better management decisions. The rice farming systems in this study comprise rice farms using traditional practices and those using some or all of the recommended system of rice intensification (SRI) practices. The overall results show 2% and zero probability of net cash income (NCI) being negative for partial and full SRI adopters, respectively. Meanwhile, farmers using local and improved seeds have 66% and 60% probability of NCI being negative, correspondingly. Rice farms which applied fertilizers in addition to improved seeds have a 21% probability of negative returns. Additionally, net income for rice farms using local seeds was slightly worthwhile when the transaction made during the harvesting period compared to farms applied improved varieties due to a relatively high price for local seeds. These results help to inform policymakers and agencies promoting food security and eradication of poverty on the benefits of encouraging improved rice farming practices in the country. Despite climate variability, in Tanzania, it is still possible for rice farmers to increase food production and income through the application of improved technologies, particularly SRI management practices, which have shown a promising future.Peer Reviewe

Neuromuscular blockade during therapeutic hypothermia after cardiac arrest: Observational study of neurological and infectious outcomes

AbstractIntroductionNeuromuscular blockade (NMB) is widely used during therapeutic hypothermia (TH) after cardiac arrest but its effect on patient outcomes is unclear. We compared the effects of NMB on neurological outcomes and frequency of early-onset pneumonia in cardiac-arrest survivors managed with TH.MethodsWe retrospectively studied consecutive adult cardiac-arrest survivors managed with TH in a tertiary-level intensive care unit between January 2008 and July 2013. Patients given continuous NMB for persistent shivering were compared to those managed without NMB. Cases of early-onset pneumonia and vital status at ICU discharge were recorded. To avoid bias due to between-group baseline differences, we adjusted the analysis on a propensity score.ResultsOf 311 cardiac-arrest survivors, 144 received TH, including 117 with continuous NMB and 27 without NMBs. ICU mortality was lower with NMB (hazard ratio [HR], 0.54 [0.32; 0.89], p=0.016) but the difference was not significant after adjustment on the propensity score (HR, 0.70 [0.39; 1.25], p=0.22). The proportion of patients with good neurological outcomes was not significantly different (36% with and 22% without NMB, p=0.16). Early-onset pneumonia was more common with NMB (HR, 2.36 [1.24; 4.50], p=0.009) but the difference was not significant after adjustment on the propensity score (HR, 1.68 [0.90; 3.16], p=0.10).ConclusionsContinuous intravenous NMB during TH after cardiac arrest has potential owns effects on ICU survival with a trend increase in the frequency of early-onset pneumonia. Randomised controlled trials are needed to define the role for NMB among treatments for TH-induced shivering

Musculoskeletal Injuries and Outcomes Pre- and Post- Emergency Medicine Training Program

Introduction: Musculoskeletal injuries (MSI) comprise a large portion of the trauma burden in low- and middle-income countries (LMIC). Rwanda recently launched its first emergency medicine training program (EMTP) at the University Teaching Hospital-Kigali (UTH-K), which may help to treat such injuries; yet no current epidemiological data is available on MSI in Rwanda.Methods: We conducted this pre-post study during two data collection periods at the UTH-K from November 2012 to July 2016. Data collection for MSI is limited and thus is specific to fractures. We included all patients with open, closed, or mixed fractures, hereafter referred to as MSI. Gathered information included demographics and outcomes including death, traumatic complications, and length of hospital stay, before and after the implementation of the EMTP.Results: We collected data from 3609 patients. Of those records, 691 patients were treated for fractures, and 674 of them had sufficient EMTP data measured for inclusion in the analysis of results (279 from pre-EMTP and 375 from post-EMTP). Patient demographics demonstrate that a majority of MSI cases are male (71.6% male vs 28.4% female) and young (64.3% below 35 years of age). Among mechanisms of injury, major causes included road traffic accidents (48.1%), falls (34.2%), and assault (6.0%). There was also an observed association between EMTP and trends of the three primary outcomes: a reduction of death in the emergency department (ED) from those with MSI by 89.9%, from 2.51% to 0.25% (p = 0.0077); a reduction in traumatic complications for MSI patients by 71.7%, from 3.58% to 1.01% (p = 0.0211); and a reduction in duration of stay in the ED among those with MSI by 52.7% or 2.81 days on average, from 5.33 to 2.52 days (p = 0.0437).Conclusion: This study reveals the current epidemiology of MSI morbidity and mortality for a major Rwandan teaching hospital and the potential impacts of EM training implementation among those with MSI. Residency training programs such as EMTP appear capable of reducing mortality, complications, and ED length of stay among those with MSI caused by fractures. Such findings underscore the efficacy and importance of investments in educating the next generation of health professionals to combat prevalent MSI within their communities