Aplicación de algunos modelos de series temporales al mercado de la electricidad en España

Hoy día, todo el mundo tiene un ojo puesto en el Mercado Eléctrico en nuestro país. No existe duda alguna sobre la importancia que tiene el comportamiento de la demanda eléctrica. Una de las peculiaridades de la electricidad que producimos, es que hoy por hoy, no existen aún métodos lo suficientemente efectivos para almacenarla, al menos en grandes cantidades. Por consiguiente, la cantidad demandada y la ofertada/producida deben casar de manera casi perfecta. Debido a estas razones, es bastante interesante tratar de predecir el comportamiento futuro de la demanda, estudiando una posible tendencia y/o estacionalidad. Profundizando más en los datos históricos de las demandas; es relativamente sencillo descubrir la gran influencia que la temperatura ambiente, laboralidad o la actividad económica tienen sobre la respuesta de la demanda. Una vez teniendo todo esto claro, podemos decidir cuál es el mejor método para aplicarlo en este tipo de series temporales. Para este fin, los métodos de análisis más comunes han sido presentados y explicados, poniendo de relieve sus principales características, así como sus aplicaciones. Los métodos en los que se ha centrado este proyecto son en los modelos de alisado y medias móviles. Por último, se ha buscado una relación entre la demanda eléctrica peninsular y el precio final que pagamos por la luz.

Ascertaining Key Factors Behind the Coexistence of the Native Ant Species Plagiolepis pygmaea with the Invasive Argentine Ant Linepithema humile (Hymenoptera: Formicidae)

The Argentine ant, Linepithema humile, is a world-wide invasive ant species. Its presence has a strong negative impact on ant diversity. The present study attempts to highlight the reasons for the coexistence of this highly dominant species with Plagiolepis pygmaea, the only native ant species that has proved able to resist the invasion in a natural ecosystem in the north-east of the Iberian Peninsula. To quantify the aggressiveness level of both species we performed aggressiveness tests on workers in different areas: a) Argentine ant workers from areas with P. pygmaea, b) Argentine ant workers from areas without P. pygmaea, c) P. pygmaea from a non-invaded area and d) P. pygmaea from an invaded area. We also confronted Argentine ant workers with P. pallidula and T. nigerrimum. These aggressiveness tests showed that the coexistence of these two species of ants was not due to a habituation process, since the aggressiveness level observed between the four kinds of confrontations were fairly similar. We also found a lack of aggressiveness between Argentine ant workers and P. pygmaea, and highly submissive behavior in the latter when confronted with the invader. The peaceful character of P. pygmaea together with its markedly submissive behavior may be the main factors behind the coexistence of these species in the study area

La Palma - Nova Classis: a Publius Cornelius Scipio Africanus encampment during the Second Punic War in Iberia

This paper presents the discovery of the oldest Roman camp on the Iberian Peninsula, a camp from the Second Punic War situated in La Palma (Tarragona, Spain), by the mouth of the River Ebro. Although no structural remains have been found, the site's strategic in- terest along with many coins, arms and fragments of amphoras and other objects indicate that a military camp was established here between 218 and 209 BC. Written sources, mainly Polybius and Livy, suggest that La Palma was where the legions of Publius Cornelius Scipio gathered before the attack on Carthago Nova in 209 BC. The paper ends by suggesting that La Palma may be the Roman camp of Nova Classis mentioned by Livy during the events of the war in 217 BC.

Presence of the Nearctic Water Boatman Trichocorixa Verticalis Verticalis (Fieber, 1851) (Heteroptera, Corixidae) in the algarve region (S Portugal)

This paper describes the presence of the nearctic water boatman Trichocorixa verticalis verticalis in southern Portugal. This species has been cited recently for the first time in Europe from individuals captured in southern Spain. This species, native to Atlantic coast of America, has also been cited from New Caledonia and South Africa, and has been found in the open sea. Two kinds of introduction are reported for this species: involuntary introduction with exotic fish, and passive dispersion through marine currents and severe storms. The possibility of this kind of introduction in Europe is discussed

Rhaponticum repens (Compositae), una nueva planta alóctona para la Península Ibérica

First record of the alien pest Rhaponticum repens (Compositae) in the Iberian Peninsula.- Rhaponticum repens is reported for the first time for the flora of the Iberian Peninsula. The species is native from Central Asia and has become invasive in Argentina, Canada, Europe and the USA. It was detected for the first time in abandoned fields from Vilablareix, near the city of Girona (Catalonia, Spain) and in the valley of the Vinalopó in Alicante (Valencia, Spain), where it was collected as early as in 1959 but misdentified. Molecular data, based on nrDNA region ITS, suggest that the reported populations may be closely related to plants from the United States. Due to the extremely noxious character of the species and the possible relationship of Spanish plants with the invasive American populations, some kind of monitoring is recommended

Temperature-Specific Competition between Invasive Mosquitofish and an Endangered Cyprinodontid Fish

Condition-specific competition is widespread in nature. Species inhabiting heterogeneous environments tend to differ in competitive abilities depending on environmental stressors. Interactions between these factors can allow coexistence of competing species, which may be particularly important between invasive and native species. Here, we examine the effects of temperature on competitiveinteractions between invasive mosquitofish, Gambusia holbrooki, and an endemic Iberian toothcarp, Aphanius iberus. We compare the tendency to approach heterospecifics and food capture rates between these two species, and examine differences between sexes and species in aggressive interactions, at three different temperatures (19, 24 and 29uC) in three laboratory experiments. Mosquitofish exhibit much more aggression than toothcarp. We show that mosquitofish have the capacity to competitively displace toothcarp through interference competition and this outcome is more likely at higher temperatures. We also show a reversal in the competitive hierarchy through reduced food capture rate by mosquitofish at lower temperatures and suggest that these two types of competition may act synergistically to deprive toothcarp of food at higher temperatures. Males of both species carry out more overtly aggressive acts than females, which is probably related to the marked sexual dimorphism and associated mating systems of these two species. Mosquitofish may thus impact heavily on toothcarp, and competition from mosquitofish, especially in warmer summer months, may lead to changes in abundance of the native species and displacement to non-preferred habitats. Globally increasing temperatures mean that highly invasive, warm-water mosquitofish may be able to colonize environments from which they are currently excluded through reduced physiological tolerance to low temperatures. Research into the effects of temperature on interactions between native and invasive species is thus of fundamental importance

Estudio de alta resolución de las fallas activas y procesos sedimentarios asociados al Cañón de São Vicente, margen Sudoeste de Iberia

The Southwest Iberian Margin is caracterized by an intense and diffuse seismic activity due to the convergence between Eurasian and African plates...

Physico-chemical analysis of Albian (Lower Cretaceous) amber from San Just (Spain): implications for palaeoenvironmental and palaeoecological studies.

Amber from a Lower Cretaceous outcrop at San Just, located in the Eastern Iberian Peninsula (Escucha Formation, Maestrat Basin), was investigated to evaluate its physico-chemical properties. Thermogravimetric (TG) and Differential Thermogravimetric (DTG) analyses, infra-red spectroscopy, elemental and C-isotope analyses were performed. Physico-chemical differences between the internal light nuclei and the peripheral darker portions of San Just amber can be attributed to processes of diagenetic alteration that preferentially took place in the external amber border colonized by microorganisms (fungi or bacteria) when the resin was still liquid or slightly polymerized. δ13Camber values of different pieces of the same sample, from the nucleus to the external part, are remarkably homogeneous, as are δ13Camber values of the darker peripheral portions and lighter inner parts of the same samples. Hence, neither invasive microorganisms, nor diagenetic alteration, changed the bulk isotopic composition of the amber. δ13C values of different amber samples range from -21.1 to -24 , as expected for C3 plant-derived material. C-isotope analysis, coupled to palaeobotanical, TG and DTG data and infra-red spectra, suggests that San Just amber was exuded by only one conifer species, belonging to either the Cheirolepidiaceae or Aracauriaceae, coniferous families probably living under stable palaeoenvironmental and palaeoecological conditions.

La terra sigillata hispánica tardía (TSHT) en la costa este de Hispania. Una aproximación general

Se recopila la información existente sobre la difusión de la terra sigillata hispánica tardía (TSHT) en el litoral mediterráneo de Hispania, concretamente en las actuales Cataluña, Comunidad Valenciana y Baleares. Se analizan los contextos arqueológicos conocidos con la finalidad de determinar la cronología y la presencia porcentual de este tipo cerámico en le levante peninsular.

Environmental factors, spatial variation, and specific requirements of Chironomidae in Mediterranean reference streams

Chironomidae spatial distribution was investigated at 63 near-pristine sites in 22 catchments of the Iberian Mediterranean coast. We used partial redundancy analysis to study Chironomidae community responses to a number of environmental factors acting at several spatial scales. The percentage of variation explained by local factors (23.3%) was higher than that explained by geographical (8.5%) or regional factors(8%). Catchment area, longitude, pH, % siliceous rocks in the catchment, and altitude were the best predictors of Chironomidae assemblages. We used a k-means cluster analysis to classified sites into 3 major groups based on Chironomidae assemblages. These groups were explained mainly by longitudinal zonation and geographical position, and were defined as 1) siliceous headwater streams, 2) mid-altitude streams with small catchment areas, and 3) medium-sized calcareous streams. Distinct species assemblages with associated indicator taxa were established for each stream category using IndVal analysis. Species responses to previously identified key environmental variables were determined, and optima and tolerances were established by weighted average regression. Distinct ecological requirements were observed among genera and among species of the same genus. Some genera were restricted to headwater systems (e.g., Diamesa), whereas others (e.g., Eukiefferiella) had wider ecological preferences but with distinct distributions among congenerics. In the present period of climate change, optima and tolerances of species might be a useful tool to predict responses of different species to changes in significant environmental variables, such as temperature and hydrology.

"Vinci Cosmetics" Fabricación y comercialización de productos cosméticos

Contexto: La idea principal es la creación de una empresa para la fabricación y comercialización de productos cosméticos de alta gama. A pesar del contexto de crisis económica en el que estamos envueltos estos últimos años y del que no parece que acabamos de salir, el sector de la cosmética está resistiendo la situación de forma envidiable. De la crisis, como dicen los economistas, “se saldrá y se volverá, todo es cíclico” y viendo la fortaleza que éste sector está mostrando unido a la necesidad de que nuestra economía abandone sectores muy deteriorados y sin una previsión positiva de futuro, la cosmética se postula con un futuro prometedor dentro del contexto económico español y europeo. “Vinci Cosmetics” es el nombre inicialmente pensado para que la nueva compañía inicie su andadura. Nombre con tintes latinos de la lejana época del imperio romano como homenaje a la rica herencia histórica de la ciudad del autor del proyecto - Tarragona. La cultura por cuidarse y sentirse bien, muy arraigada en la mentalidad latina y mediterránea, es un factor cultural clave para el desarrollo y futura evolución de esta industria. El slogan de la empresa, “Dieta Mediterránea para tu piel”, clarifica en buena medida la idea a desarrollar y los objetivos pretendidos por la estrategia empresarial. Objetivos: El objetivo esencial del TFC es elaborar un estudio detallado para la creación de una empresa de fabricación y comercialización de productos cosméticos de alta gama que abarque el management y la gestión por procesos de la empresa, la función de marketing, el tipo de operaciones y procesos a realizar, la gestión del factor humano y el presupuesto necesario para cubrir este ambicioso proyecto. En detalle, un completo plan de empresa que marque las directrices de la organización industrial que se pretende crear compuesto a su vez por cinco planes: plan de gerencia, plan de marketing, plan de operaciones, plan de recursos humanos y plan económico – financiero. Procedimientos: El proyecto tiene un alto componente de estudio de mercados y de marketing pero pretende también abarcar el management, los procesos de operación, el factor humano y el aspecto económico y financiero de las inversiones y presupuesto necesario. El estudio inicial centrará su esfuerzo en un análisis del mercado de la península ibérica, y, en función del avance y del progreso esperado por la empresa, la compañía podría extender su campo de acción a Europa aunque no antes de un medio plazo. “Vinci Cosmetics” ha adoptado referenciales de sistemas de gestión integrados en toda la organización. Así tenemos principalmente, por un lado, la norma internacional ISO 9001:2008 y, por otro, el Modelo EFQM de Excelencia en la gestión; ambos plasmados a partir de un enfoque basado en procesos que nos garantiza el control continuo y la gestión excelente. Conclusiones: Tras evaluar la situación actual del mercado de la cosmética, las previsiones futuras de éste y las necesidades que una organización industrial necesita, se puede crear - con plenas garantías de éxito como organización empresarial y desde el punto de vista económico - una empresa de cosméticos de alta gama para cubrir las necesidades de una parte de mercado que lo requiere.