- DUOPOLY PRICE COMMUNICATION

We investigate the role of price communication in imperfect information environments by setting up a dynamic differentiated duopoly where actions are not observable and where firms decide, before pricing, whether to communicate their choices to the rivals. When firms play simultaneously in the pricing stages, communication across them is a dominant strategy allowing firms to coordinate prices, thus reducing competition. However, when communication takes place within pricing stages, this meaning that firms are given the opportunity to choose roles, the above firms coordination in prices is mitigated. This is because of the existence of a second mover advantage effect. Communication by the leader acts as a pre-commitment device to a price umbrella that the follower will undercut. As a result, we end up with a more competitive situation although price levels will not go down to those without communication.commitment, price communication

Efectos alelopáticos de extractos acuosos de arvenses sobre la germinación de trigo duro y Lolium Rigidum

We analyzed the allelopathic effects of aqueous extracts of plants on durum wheat (Triticum durum Desf.) and Lolium rigidum Gaud., together with joint germination of both plants. Results showed that several extracts stimulated root development and hypocotyl, being proportional to the concentration of the extract, highlighting Urtica sp., Chenopodium murale, Sinapis arvensis and Diplotaxis virgata while Matricaria chamomilla inhibited growth. The extracts tested on L. rigidum decreased root development in the case of Malva parviflora, Daucus carota, Plantago lanceolata, Borago sp. and Papaver rhoeas. Moreover, the joint seed germination of T. durum and L. rigidum resulted in increased both germination and root development of both species.Se han analizado los efectos alelopáticos de extractos acuosos de varias plantas sobre trigo duro (Triticum durum Desf.) y Lolium rigidum Gaud., y la germinación conjunta de las semillas de ambas especies. Los resultados han mostrado que varios extractos estimularon el desarrollo radicular y del hipocótilo, siendo el efecto proporcional a la concentración del extracto, destacando Urtica sp., Chenopodium murale, Sinapis arvensis y Diplotaxis virgata, mientras que Matricaria chamomilla inhibió el crecimiento. Los extractos ensayados sobre L. rigidum disminuyeron el desarrollo radicular en el caso de Malva parviflora, Daucus carota, Plantago lanceolata, Borago sp. y Papaver rhoeas. Por otra parte, la germinación conjunta de semillas del trigo duro y L. rigidum incrementó la germinación y el desarrollo radicular de ambas especie

Epigraphic news in the middle Ebro (La Rioja)

En la primera parte de este trabajo se dan a conocer siete nuevas inscripciones en piedra de territorio riojano, conteniendo información novedosa principalmente sobre el ejército y las comunicaciones antiguas. En la segunda parte se recogen las inscripciones de nueve vasos cerámicos, hallados en Vareia (Varea, Logroño) y producidos en Calagurris Iulia por el officinator de esa ciudad G. Valerius Verdullus; son un magnífico exponente de la romanización del Ebro al final del período julio-claudio.The first part of this paper deals with seven new inscriptions over stone found in the territory of La Rioja, which give new information mainly about the army and the old communications. The second part deals with the inscriptions over nine ceramic vases found in Vareia (Varea, Logroño) and made in Calagurris Iulia by G. Valerius, the officinator of that town. They are a magnificent proof of the romanization of the Ebro at the end of the period JuliusClaudius

Effect of agro-climatic conditions on near infrared spectra of extra virgin olive oils

Authentication of extra virgin olive oil requires fast and cost-effective analytical procedures, such as near infrared spectroscopy. Multivariate analysis and chemometrics have been successfully applied in several papers to gather qualitative and quantitative information of extra virgin olive oils from near infrared spectra. Moreover, there are many examples in the literature analysing the effect of agro-climatic conditions on food content, in general, and in olive oil components, in particular. But the majority of these studies considered a factor, a non-numerical variable, containing this meteorological information. The present work uses all the agro-climatic data with the aim of highlighting the linear relationships between them and the near infrared spectra. The study begins with a graphical motivation, continues with a bivariate analysis and, finally, applies redundancy analysis to extend and confirm the previous conclusions.Peer Reviewe

An Algorithm for the Single-Input Pole Assignment Problem

[EN] B. N. Datta and K. Datta have proposed an efficient parallel algorithm for the single-input pole assignment problem when the spectrum set to be assigned is pairwise distinct and disjoint from the spectrum of the dynamical matrix. This paper first presents a theoretical analysis of that algorithm and then presents the necessary modifications on it for an arbitrary spectrum. Based on the modified algorithm, the authors present two new algorithms for the problem and give some results on controllability that are of independent interests.Bru, R.; Mas Marí, J.; Urbano Salvador, AM. (1994). An Algorithm for the Single-Input Pole Assignment Problem. SIAM Journal on Matrix Analysis and Applications. 15(2):393-407. doi:10.1137/S0895479889161125S39340715

Predicting seedling emergence of three canarygrass (Phalaris) species under semi-arid conditions using parametric and non-parametric models

The Phalaris genus includes annual weed species such as short-spiked canarygrass (Phalaris brachystachys Link.), little-seed canarygrass (Phalaris minor Retz.) and hood canarygrass (Phalaris paradoxa L.), which are especially problematic in Spain; as such, there is a need to develop models to predict the timing of their emergence. Field experiments were conducted at two different locations during two (2006/07 and 2007/08) and three (from 2005/06 to 2007/08) growing seasons. In both locations, 500 seeds of each Phalaris species were sown each growing season, simulating rain-fed cereal field conditions. In addition, the models were validated with three, four and eight independent experiments for P. brachystachys, P. minor and P. paradoxa, respectively. The emergence period of the three Phalaris species lasted between 31 and 48 days after sowing (DAS), showing two main flushes. The three cardinal points for parametric and non-parametric models were established to be between −1 ◦C and 1 ◦C for base temperature, between 9.8 ◦C and 11.8 ◦C for optimal temperature and between 21.2 ◦C and 23.4 ◦C for ceiling temperature; base water potential was estimated to be between −1 and −1.1 MPa. Both parametric and non-parametric models obtained similar results and were successfully validated in 12 out of 15 independent experiments.This research and the APC were both funded by CATEDRA ADAMA. European Regional Development Funds (FEDER) and the Spanish Ministry of Economy and Competitiveness funds (AGL2005-0405) also supported data collection between 2005 and 200