On stabilization policy in sunspot-driven oligopolistic economies

Economies with oligopolistic markets are prone to inefficient sunspot fluctuations triggered by autonomous changes in firms equilibrium conjectures. We show that a well designed taxation-subsidization scheme can eliminate these fluctuations by coordinating firms in each sector on a single efficient equilibrium. At the macroeconomic level, implementing this stabilization policy leads to significant welfare gains, attributable to a quantitatively dominant "efficient stabilization effect". This effect, while important, is typically ignored in the traditional computations of the welfare costs of aggregate fluctuations (e.g., Lucas, 2003)

Free entry equilibria with positive profits: A unified approach to quantity and price competition games

Free entry equilibria are usually characterized by the zero profit condition. We plead instead for a strict application of theNash equilibriumconcept to a symmetric simultaneous game played by actual and potential entrants, producing under decreasing average cost. Equilibrium is then typically indeterminate, with a number of active firms varying between an upper bound imposed by profitability and a lower bound required by sustainability. We use a canonical model with strategies represented by prices, although covering standard regimes of quantity and price competition, to show that in equilibrium the critical (profit maximizing) price must lie between the break-even and the limit prices

O espaço das desigualdades educativas em São Paulo e em Recife

Neste artigo nós apresentamos um estudo empírico sobre as clivagens sociais e educacionais Recife e São Paulo, cidades caracterizadas pela urbanização acelerada e configurações urbanas fortemente desiguais. Com base na noção de espaço social e, em dados estatísticos do último Censo Populacional (IBGE/ 2010), apresenta-se um estudo sobre o espaço das disparidades educacionais nas duas metrópoles. O objetivo foi testar a pertinência da noção de espaço social no contexto brasileiro, identificando de uma só vez, a distribuição dos grupos sociais e seus investimentos educativos. Argumenta-se que a noção de espaço social é capaz de integrar vários outros conceitos chaves da sociologia bourdiesiana. Mobilizamos um grande conjunto de variáveis capturadas simultaneamente, trazendo à tona as diferenças internas das duas metrópoles e entre as cidades. A originalidade do estudo reside em partir dessa gama ampla de indicadores objetivos, relativos às condições de vida, associando-o ao uso de indicadores suscetíveis de serem percebidos como “subjetivos”. Como esperado, o primeiro eixo corresponde a uma forte correlação entre longevidade, renda domiciliar e nível de escolaridade. O segundo eixo é o resultado da correlação entre a posse do diploma de ensino secundário e a presença de maior infraestrutura pública. Em Recife, esse segundo eixo concerne a alguns bairros da cidade. Em São Paulo observa-se a mesma correlação, contudo, com a particularidade de apresentar um conjunto muito maior de bairros em posições sociais intermediárias. Nota-se ainda que Recife possui um número muito maior de regiões em situação de extrema pobreza se comparado à São Paulo

Comparative kinetic analysis of two fungal β-glucosidases

<p>Abstract</p> <p>Background</p> <p>The enzymatic hydrolysis of cellulose is still considered as one of the main limiting steps of the biological production of biofuels from lignocellulosic biomass. It is a complex multistep process, and various kinetic models have been proposed. The cellulase enzymatic cocktail secreted by <it>Trichoderma reesei </it>has been intensively investigated. β-glucosidases are one of a number of cellulolytic enzymes, and catalyze the last step releasing glucose from the inhibitory cellobiose. β-glucosidase (BGL1) is very poorly secreted by <it>Trichoderma reesei </it>strains, and complete hydrolysis of cellulose often requires supplementation with a commercial β-glucosidase preparation such as that from <it>Aspergillus niger </it>(Novozymes SP188). Surprisingly, kinetic modeling of β-glucosidases lacks reliable data, and the possible differences between native <it>T. reesei </it>and supplemented β-glucosidases are not taken into consideration, possibly because of the difficulty of purifying BGL1.</p> <p>Results</p> <p>A comparative kinetic analysis of β-glucosidase from <it>Aspergillus niger </it>and BGL1 from <it>Trichoderma reesei</it>, purified using a new and efficient fast protein liquid chromatography protocol, was performed. This purification is characterized by two major steps, including the adsorption of the major cellulases onto crystalline cellulose, and a final purification factor of 53. Quantitative analysis of the resulting β-glucosidase fraction from <it>T. reesei </it>showed it to be 95% pure. Kinetic parameters were determined using cellobiose and a chromogenic artificial substrate. A new method allowing easy and rapid determination of the kinetic parameters was also developed. β-Glucosidase SP188 (K_m= 0.57 mM; K_p= 2.70 mM) has a lower specific activity than BGL1 (K_m= 0.38 mM; K_p= 3.25 mM) and is also more sensitive to glucose inhibition. A Michaelis-Menten model integrating competitive inhibition by the product (glucose) has been validated and is able to predict the β-glucosidase activity of both enzymes.</p> <p>Conclusions</p> <p>This article provides a useful comparison between the activity of β-glucosidases from two different fungi, and shows the importance of fully characterizing both enzymes. A Michaelis-Menten model was developed, including glucose inhibition and kinetic parameters, which were accurately determined and compared. This model can be further integrated into a cellulose hydrolysis model dissociating β-glucosidase activity from that of other cellulases. It can also help to define the optimal enzymatic cocktails for new β-glucosidase activities.</p

Phase equilibria of mixtures involving fatty acid ethyl esters and fat alcohols between 4 and 27 kPa for bioproduct production

The aim of this paper is to bring valuable phase equilibria information for the design and operation of biolubricant and related biofuel product processes. As a result, Vapor-Liquid Equilibrium (VLE) measurements, at different temperatures, pressures and global compositions, for the ternary systems [Ethanol + 2-Ethyl-1-hexanol + 1-Dodecanol] and [Ethanol + 1-Octanol + 1-Dodecanol], as well as a multicomponent system containing these alcohols together with Balanites aegyptiaca fatty acid ethyl esters are reported for the first time (data pressure and temperature ranges: 4394–26790 Pa, 306–423 K). The Dortmund modified UNIFAC model showed very high accuracy in the prediction of these VLE, with overall average absolute deviations on the liquid and vapor molar compositions of 0.007 and 0.0003 for the ternary systems, 0.003 and 0.006 for the multicomponent system.The authors express their acknowledgments to the ENSIC students who contributed to this work through their Master 1 training. S.P.P. thanks support to project CIMO-Mountain Research Center, UIDB/00690/2020, financed by national funds through the Portuguese Foundation for Science and Technology/MCTES.info:eu-repo/semantics/publishedVersio

Seasonal effect on spatial and temporal consistency of the new GPM-based IMERG-v5 and GSMaP-v7 satellite precipitation estimates in Brazil’s Central Plateau Region

This study assesses the performance of the new Global Precipitation Measurement (GPM)-based satellite precipitation estimates (SPEs) datasets in the Brazilian Central Plateau and compares it with the previous Tropical Rainfall Measurement Mission (TRMM)-era datasets. To do so, the Integrated Multi-satellitE Retrievals for GPM (IMERG)-v5 and the Global Satellite Mapping of Precipitation (GSMaP)-v7 were evaluated at their original 0.1 spatial resolution and for a 0.25 grid for comparison with TRMM Multi-satellite Precipitation Analysis (TMPA). The assessment was made on an annual, monthly, and daily basis for both wet and dry seasons. Overall, IMERG presents the best annual and monthly results. In both time steps, IMERG’s precipitation estimations present bias with lower magnitudes and smaller root-mean-square error. However, GSMaP performs slightly better for the daily time step based on categorical and quantitative statistical analysis. Both IMERG and GSMaP estimates are seasonally influenced, with the highest difficulty in estimating precipitation occurring during the dry season. Additionally, the study indicates that GPM-based SPEs products are capable of continuing TRMM-based precipitation monitoring with similar or even better accuracy than obtained previously with the widely used TMPA product

Determination of kinetic and stoichiometric parameters of pseudomonas putida F1 by chemostat and In situ pulse respirometry

The applicability of pulse respirometry, for the estimation of kinetic and stoichiometric parameters in pure cultures was evaluated by comparison with traditional chemostat method. Pseudomonas putida F1 was cultured in a continuous stirred tank reactor, using glucose as sole carbon source. The reactor was operated under steady-state with six dilution rates, ranging from 0.06 to 0.35 h-1. Substrate and biomass concentration were measured and used to estimate kinetic and stoichiometric parameters, according to the Monod model. An in situ respirometry method was also applied to the reactor, with the injection of pulses of glucose from 19 to 97 mg L-1. The respirograms obtained were used to estimate the kinetic and stoichiometric parameters according to ASM1 and ASM3 models. No significance difference was observed between parameters estimated by chemostat and respirometric methods. The glucose affinity constant was from 0.4 to 0.7 mg L-1, the maximum specific growth rate was from varying from 0.14 to 0.20 h-1, and the growth yield was from 0.41 to 0.67. These results confirm that in situ pulse respirometry is a suitable method for kinetic and stoichiometric parameters estimation.Fundação para a Ciência e a Tecnologia (FCT)Consejo Nacional de Ciencia y Tecnología (Mexico)We gratefully acknowledge the financial support to Catarina S. Oliveira through the grant SFRH/BD/32289/2006 from the Fundac¸ao para a Ciência e a Tecnologia (Portugal), and to Alberto Ordaz through the grant #208321 from the Consejo Nacional de Ciencia y Tecnología (Mexico)

Etude des apprentissages olfactifs alimentaires (importance de l'amygdale basolatérale et du cortex insulaire chez le rat.)

Dans la perspective de mieux comprendre les mécanismes impliqués dans les apprentissages olfactifs alimentaires, nous avons investigué les bases neurobiologiques de l aversion olfactive conditionnée (AOC) et de la préférence olfactive conditionnée (POC). Nous nous sommes intéressés au rôle joué par deux structures de convergence des informations olfactives, gustatives et viscérales, le noyau basolatéral de l amygdale (NBL) et le cortex insulaire (CI). Une approche pharmacologique nous permet de montrer que le NBL est indispensable à l acquisition, la consolidation et le rappel de l AOC. A contrario, le CI n est nécessaire à aucune de ces étapes mnésiques. Grâce à une technique d imagerie cellulaire (catFISH), nous observons que l apprentissage de la POC s accompagne d une augmentation de la convergence des informations odeur-goût au sein des neurones du NBL mais pas du CI, due à un recrutement d une nouvelle population neuronale. Que l approche soit systémique ou cellulaire, qu elle intéresse un apprentissage aversif ou appétitif, nos études soulignent l importance du NBL dans la mémoire olfactive alimentaire.To better understand the mechanisms involved in food olfactory learning, the neurobiological basis of conditioned odor aversion (COA) and the conditioned odor preference (COP) were investigated. We study the basolateral amygdala (BLA) and the insular cortex (IC), which receive olfactory, gustatory and visceral information. Using a pharmacological approach, we show that the BLA is involved in acquisition, consolidation and both recent and remote memory retrieval of COA. By contrast, the IC is not necessary to any of these memory phases. Using a cellular imaging technique (catFISH), we find that COP leads to an increase of odor-taste convergence onto individual neurons in the BLA, but not the IC, by means of the recruitment of a new population. Whether the approach is systemic or cellular and the learning is aversive or appetitive, our study highlights the importance of the BLA in food olfactory learning.TOURS-Bibl.électronique (372610011) / SudocSudocFranceF

A science-gateway workload archive application to the self-healing of workflow incidents

Information about the execution of distributed workload is important for studies in computer science and engineering, but workloads acquired at the infrastructure-level reputably lack information about users and application-level middleware. Meanwhile, workloads acquired at science-gateway level contain detailed information about users, pilot jobs, task sub-steps, bag of tasks and workflow executions. In this work, we present a science-gateway archive, we illustrate its possibilities on a few case studies, and we use it for the autonomic handling of workflow incidents