Were The Peseta Exchange Rate Crises Forecastable During Target Zone Period?

During the 1990’s several fixed or quasi-fixed exchange rate systems collapsed. Currency crises have happened in both developed and emerging countries so it is necessary to forecast and avoid them. However, financial market crises have been extremely di¢cult to forecast. Economic agents’ expectations are non-observable variables that cannot be ignored in our models. In addition, if we want to study the European case during the 1990’s, the censored disposition of the exchange rate cannot be ignored either. We propose a discrete time target zones model where these aspects are taken into account. It will be tested in a peseta/deutsche mark exchange rate framework, from June 1989 to December 1998. The results indicate differences between before and after the shift in band widths in August 1993.Target Zones, Currency Crises, Mean Reversion, Realignment Probability

Exchange rate dynamics in crawling-band systems

In this note we show that an exchange rate crawling-band system can borrow a portion of those aspects of a target zone that lead to its stabilizing effects on the exchange rate, depending on the relationship between the crawl rate and the drift of the fundamentals process. If the crawl rate is sufficiently high (with respect to the drift), the crawling-band is similar to a free float regime. As the crawl rate decreases, the crawling-band system collapses to a standard target zone.crawling band

Business Cycle and Speculative Pressures in a Target Zone

In the past time, most economies have suffered cyclical fluctuations in their activity which may influence the optimal use of productive factors in long slow-growth phases or price stability in periods of fast growth. This paper focuses on the possible interrelationship between business cycles and exchange rate ‡uctuations. We have chosen the European Monetary System framework in the nineties, from June 1989 to December 1998, because the Peseta belonged to the EMS during that time. This sample is specially interesting because it includes the worst crisis of the System in 1992-93 and the following ones affecting emerging countries like Mexico, Brazil or Russia at the end of the decade. We use a Binary Dependent Variable Logit Model to estimate the readjustment probability inside a band for two currencies, the Peseta and the french Franc . We calculate the dependent variable values from a Markov-Switching Regime Model with constant transition probabilities. We prove that it is a suitable method and that it allows both real and monetary variables to be identified in order to explain speculative pressures.Readjustment Probability, Speculative Pressures, Economic Fluctuations.

Nuevas aportaciones sedimentológicas y cronoestratigráficas sobre las Fms. Higueruelas y Villar del Arzobispo en Benagéber (NO de Valencia)

Peer reviewe

Biological and microbial activity in biological soil crusts from the Tabernas desert, a sub-arid zone in SE Spain.

The ecology and functional role of biological soil crusts (BSCs) in arid and semi-arid zones have been extremely well studied. However, little is known about the biochemical properties related to the number and activity of the microbiota that form the crusts, even though information about these properties is very important for understanding many of the processes that affect the formations. In this study, several properties related to the activity and number of microorganisms (biomass-C, basal respiration, dehydrogenase activity and nitrogen mineralization potential) were determined at different depths (crusts, 0-0.5 cm; middle, 0.5-3 cm and deep, 3-5 cm layers) in two types of crusts (predominated by cyanobacteria and by lichens) in the Tabernas desert (Almeria, SE Spain). The absolute values of the above-mentioned properties and the values expressed relative to the total organic carbon (TOC) content were both much higher in the crust layers than in the surface horizons of soils under Mediterranean or Atlantic climates. A large part of the TOC in the BSCs was contained in the microbiota and another large part was readily metabolized during incubation of the crusts for 10 days at 25 °C. The net nitrogen mineralization rate was also high, and ammonification predominated in the crust layers, whereas nitrification predominated in the middle and deep layers. In all types of BSCs, the microbiota colonized the deep layers, although with greater intensity in the lichen-dominated BSCs than in the cyanobacterial BSCs. The results also indicate that hydrolytic enzymes are not stabilized on soil colloids and their activity depends only on the active microbiota.Peer reviewe

VALORES ORGANIZACIONAIS: EVIDÊNCIAS DE VALIDADE PARA UM INSTRUMENTO DE MEDIDA

This study aimed to fi nd evidence for the validity of Organizational Values Inventory (IVO) based on its relationships with other variables. In order to fi nd them, the Job Satisfaction Scale (EST) and the Scale for Assessment of Quality of Work Life (Escala-QVT) were used. The study included 213 people, from several Brazilian states, of both sexes and with ages ranging between 17 and 71 years. In terms of education, 95.3% (203) of the sample had incomplete or complete college or undergraduate levels. The length of service in the organization ranged between one and 31 years and reported hierarchical levels ranged from top management of the organization to non-managerial positions. The results showed positive and statistically significant correlations between all IVO factors and all EST and Scale-QVT factors, with magnitudes ranging from weak to moderate for both scales, which can be taken as evidence for the validity of the instruments, especially for the case of IVO which was the focus of this study.El objetivo fue buscar evidencias de validez para el Inventario de Valores Organizacionales (IVO) por medio de sus relaciones con otras variables. Se utilizaron la Escala de Satisfacción en el Trabajo (EST) y la Escala de Evaluación de la Calidad de Vida en el Trabajo (Escala-QVT). Participaron 213 personas, con edades entre 17 y 71 años, de ambos sexos y de diversos estados brasileños. La mayoría de los participantes (95,3%) tenían nivel superior incompleto, completo o postgrado. El tiempo de trabajo en la organización fue entre uno y 31 años y los niveles jerárquicos informados fueron desde la presidencia de la organización hasta posiciones no gerenciales. Los resultados mostraron correlaciones positivas y estadísticamente signifi cativas entre todos los factores del IVO y todos los factores de la EST y de la Escala-QVT, con magnitudes oscilando entre bajas y moderadas, lo que puede ser considerado una evidencia de validez para los instrumentos, en especial para el IVO, enfoque de este estudio.O objetivo foi buscar evidências de validade para o Inventário de Valores Organizacionais (IVO) por meio de suas relações com outras variáveis. Foram utilizadas a Escala de Satisfação no Trabalho (EST) e a Escala de Avaliação da Qualidade de Vida no Trabalho (Escala-QVT). Participaram 213 pessoas, com idades variando de 17 a 71 anos, homens e muheres, oriundas de diversos estados brasileiros. A maioria dos participantes (95.3%) possuía nível superior incompleto, completo ou pós-graduação. O tempo de serviço na organização variou entre um e 31 anos e os níveis hierárquicos reportados variaram desde a presidência da organização até posições não gerenciais. Os resultados mostraram correlações positivas e estatisticamente significativas entre todos os fatores do IVO e todos os fatores da EST e da Escala-QVT, com as magnitudes variando entre fracas e moderadas, o que pode ser assumido como evidências de validade para os instrumentos, em especial para o IVO, foco deste estudo

Análise de fluxos metabólicos com substrato isotopicamente marcado (13C-MFA) em S. typhimurium

Linhagens atenuadas de Salmonella têm sido estudadas para produção e veiculação de substâncias com fins terapêuticos. Modelos metabólicos à escala genômica são ferramentas importantes no desenvolvimento de estratégias de engenharia metabólica. Este trabalho teve por objetivo obter dados experimentais para aprimorar o modelo metabólico e aprofundar o conhecimento do metabolismo de S. typhimurium (St). Foram realizados cultivos contínuos à taxa de diluição (D) de 0,24 e 0,48 h-1, utilizando U-13C-glicose como substrato. Aminoácidos da biomassa foram analisados por GC-MS. A análise de fluxos metabólicos permitiu determinar a distribuição de fluxos nas principais vias metabólicas de St. A glicólise foi a via majoritamente utilizada para catabolisar a glicose. As maiores diferenças nos fluxos estimados, para as duas D, verificaram-se nas vias anapleróticas. Sobrepondo os dados de fluxos intracelulares ao modelo metabólico será gerado um modelo mais preciso do metabolismo de S. typhimurium

LYTAG-driven purification strategies as a key to integrate and intensify the downstream processing of monoclonal antibodies

Monoclonal antibodies (mAbs) are currently the most important class of recombinant protein therapeutics in the biotechnological and biopharmaceutical industry with more than 250 mAbs currently undergoing clinical trials. High titer producing cultures and complex mixtures containing high cell densities, together with an increasing growing demand for highly pure mAbs is making recovery and purification processes hot targets for improvement and opens important technological challenges in mAbs manufacturing platforms. This work explores the use of an affinity dual ligand based on a choline binding polypeptide tag (LYTAG) fused with the synthetic antibody Z domain (LYTAG-Z) as a tool to integrate and optimized the downstream processing of mAbs. Upon addition of this ligand to an animal cell culture broth, antibody-LYTAG-Z complexes are formed which can be easily captured and separated from host cell impurities by affinity partitioning in aqueous two-phase systems (ATPS) composed of polyethylene glycol –PEG, as PEG molecules have the ability to binding to the choline binding sites of LYTAG. Integration of clarification and primary mAbs recovery was successfully accomplished using a system composed of 6% PEG 3350 Da and 7% dextran 500,000 Da in which an extraction yield of 89% and a clarification higher than 95% were achieved. IgG-rich phases were further processed by chromatography, using three different strong anion exchange matrices charged with quaternary methyl amines (a choline analogue) – CIMmultus QA, HiTrap Q FF and gPore NW Q. A two-elution method was developed for the separation of the antibody-LYTAG-Z complexe, allowing simultaneous purification of the antibody and recovery of the ligand. The process was successfully scale-up 10000 times allowing a global antibody recovery of 70% with a purity of 89% and enabling 100% cell removal