Measuring the importance of the uniform nonsynchronization hypothesis

In this paper we critically reappraise some measures of the importance of time-dependent price setting rules and propose an alternative way to gauge the significance of this type of price setting behaviour. The merits of the proposed measure are highlighted in an application using micro-data. Our results suggest that a large proportion of price trajectories may be compatible with simple time-dependent price setting mechanisms but the strength of this evidence very much depends on the way that is used to evaluate the importance of this type of behaviour. JEL Classification: D40, E31, L11perfect synchronization, Time-dependent price setting models, uniform staggering

Time or state dependent price setting rules? Evidence from Portuguese micro data

In this paper we analyse the ability of time and state dependent price setting rules to explain durations of price spells or the probability of changing prices. Our results suggest that simple time dependent models cannot be seen as providing a reasonable approximation to the data and that state dependent models are required to fully characterise the price setting behaviour of Portuguese firms. Inflation, the level of economic activity and the magnitude of the last price change emerge as relevant variables affecting the probability of changing prices. Moreover, it is seen that the impact differs for negative and positive values of these covariates. JEL Classification: C41, D40, E31CPI data, Hazard functions, inflation

Why are some prices stickier than others? Firm-data evidence on price adjustment lags

Infrequent price changes at the firm level are now well documented in the literature. However, a number of issues remain partly unaddressed. This paper contributes to the literature on price stickiness by investigating the lags of price adjustments to different types of shocks. We find that adjustment lags to cost and demand shocks vary with firm characteristics, namely the firm’s cost structure, the type of pricing policy, and the type of good. We also document that firms react asymmetrically to demand and cost shocks, as well as to positive and negative shocks, and that the degree and direction of the asymmetry varies across firms. JEL Classification: C41, D40, E31Firm heterogeneity, Panel-ordered probit, real rigidities, survey data

Modulation of phenolic production in Vitis vinifera cell cultures with Phaeomoniella chlamydospora and other elicitors

Esca is a destructive disease that affects Vitis vinífera plants around the world leading to important losses in wine production. Phaeomoniella chlamydospora (Pc) is a fungus frequently associated with esca and grapevine decline. Information on the interaction of this fungus with Vitis vinifera is scarce. To study the defense mechanisms of Vitis plants to Pc we utilized cell suspension cultures of V. vinifera cv. Vinhão (Vv) elicited with fungus Pc, methyl-jasmonate (MeJ) and salicylic acid (SA). We also used cultures primed with MeJ or SA 24h before elicitation with Pc (MeJ+Pc or SA+Pc, respectively). Several culture samples were taken during the experimental period and phenolic production was evaluated by HPLC-DAD-MSFundação para a Ciência e a Tecnologia (FCT) - SFRH/BD/17944/200

Oxidative response of Vitis vinifera cells elicited with Phaeomoniella chlamydospora

Esca is a destructive disease that affects vineyards leading to important losses in wine production, which incidence has dramatically increased during the last few years. Phaeomoniella chlamydospora (Pc) is a fungus frequently associated with esca and grapevine decline. Information on the interaction of this fungus with Vitis plants is scarce. To study early defense mechanisms, namely the oxidative response, of Vitis plants to Pc we utilized in vitro cell suspension cultures of V. vinifera cv. Vinhão (Vv) and a Pc elicitor (hydrolyzed extract).Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BD/17944/200

Psychometric properties and further validation of the emergency reaction questionnaire in a sample of Portuguese adults

Emergencies and disasters are abrupt, unexpected, dangerous events often traumatic. Individuals differ in the way they respond to this kind of adverse experience, depending on varied factors. This study used the Emergency Reaction Questionnaire (ERQ) to assess defensive mechanisms, feelings, and thoughts during emergency and disaster-related situations. The main objective of the present study was to confirm the factor structure and provide further support to the validity of the ERQ on a Portuguese sample. Here we replicated previous findings in showing that people who are more prone to react in an organized way in emergencies tend to have lower anxiety levels and a greater tendency for sensation seeking. We also found that females score lower than males; that ERQ specific readiness scores slightly increase with age and people who have risky jobs or routinely engage in extreme sports scored higher on the ERQ scales (meaning they act more readily and organized in an emergency). The ERQ and its Portuguese version show to be a psychometrically sound and valid measurement of emergency behavior, able to assess individual differences in the way people perform during various emergencies, and can be used in future research and in practice for screening or measuring training efficiency.info:eu-repo/semantics/publishedVersio

Production of transgenic Hypericum perforatum plants via particle bombardment-mediated transformation of novel organogenic cell suspension cultures

We have developed particle bombardment-mediated transformation procedure for Hypericum perforatum L. (St. John’s wort), an important medicinal species that remains highly recalcitrant towards Agrobacterium-mediated transformation. Among the major transformation techniques evaluated in the present study (Agrobacterium tumefaciens-, A. rhizogenes- and biolistics-mediated), particle-bombardment-mediated gene transfer was found to be the most successful one. GUS positive cells were obtained from organogenic nodules bombarded with the plasmid vector pCAMBIA1301 encoding an intron-containing b-glucuronidase (gusA) and hygromycin phosphotransferase (hpt) genes. After 3 months of continuous selection of bombarded nodules with 20 mg l 1 hygromycin, transgenic hygromycin-resistant callus cultures and subsequently transgenic plants were produced. PCR analysis of DNA isolated from GUS positive plants showed the presence of both gusA and hpt genes. Southern blot analysis confirmed the transgene integration and revealed diverse copy numbers and insertion sites. The data presented here demonstrate for the first time H. perforatum can be efficiently transformed via particle bombardment of organogenic cell suspension. Our results open the possibility of using particle bombardment-mediated transformation to elucidate biosynthetic pathways and to improve secondary metabolite production in H. perforatum.Fundação para a Ciência e a Tecnologia (FCT) - POCTI/AGR/40283/2001, SFRH/BPD/ 17102/200

Transgenic hypericum perforatum

Plant transformation is an important tool with many applications in modern plant biology. Although this technique is primarily used to produce superior crop varieties, it is also being utilized to answer basic questions concerning gene function and regulation in contemporary functional genomics research. In our laboratory, we have established a transformation system for Hypericum perforatum . This protocol involves the transfer of foreign DNA into H. perforatum organogenic nodule explants via particlebombardment and the regeneration of shoots from the explants under selection pressure. We have successfully used this method to express ß-glucuronidase and hygromycin phosphotransferase genes in H. perforatum . Molecular analyses of putative phenotypically normal transgenic plants show stable integration of the transgenes into the plant nuclear genome. Here we describe the procedure for the transformation of H. perforatum .Fundação para a Ciência e a Tecnologia (FCT