Effects of flow regime on the fish communities of the lower Ebro River

Els ecosistemes aquàtics presenten una estreta connexió entre forces físiques i processos ecològics. Als rius, aquesta interacció física-ecologia és dirigida pel cabal, un dels factors principals que determinen la integritat biològica. La combinació de grans alteracions hidrològiques degudes a la regulació per preses i una creixent presència d’espècies al·lòctones, posa en perill les comunitats de peixos autòctons a la Península Ibèrica. L’objectiu d’aquesta tesi és explorar les relacions entre el règim hidrològic i les comunitats de peixos del tram baix de l’Ebre per mitjà de l’anàlisi de dades de campanyes de pesca elèctrica realitzades durant més de 10 anys. Enfocàrem aquest objectiu des de tres punts de vista diferents: Al capítol 1 s’avaluaren les relacions entre les abundàncies de cada espècie i el règim hidrològic, mentre que als capítols 2 i 3, l’objecte d’estudi foren índexs de qualitat biològica basats en peixos i l’espectre de mides de la comunitat íctica, respectivament. Per descriure el règim hidrològic, férem servir un conjunt de variables calculades a partir de series diàries i horàries de cabals facilitades per la Confederació Hidrogràfica de l’Ebre (CHE). Els resultats mostraren la importància del cabal en determinar la composició íctica a nivell d’espècie, comunitat i estructura de mides. Aquests coneixements poden ser de gran utilitat pel desenvolupament d’eines de restauració ecològica i la conservació d’espècies de peixos, especialment en el context actual de creixents pressions sobre els ecosistemes d’aigua dolça (escalfament global, consum d’aigua i espècies invasores, entre d’altres).En los ecosistemas acuáticos se observa una estrecha relación entre fuerzas físicas y procesos ecológicos. En los ríos, esta interacción física-ecología está dirigida por el caudal, uno de los factores clave que determinan la integridad biológica. La combinación de grandes alteraciones hidrológicas debidas a la regulación por presas y una creciente presencia de especies introducidas, pone en peligro las comunidades piscícolas nativas de la Península Ibérica. El objetivo de esta tesis es explorar las relaciones entre el régimen hidrológico y las comunidades de peces del tramo bajo del Río Ebro mediante el análisis de datos de campañas de pesca eléctrica realizadas durante más de 10 años. Enfocamos este objetivo desde tres puntos de vista diferentes: En el Capítulo 1 se evaluaron las relaciones entre las abundancias de cada especie y el régimen hidrológico, mientras que en los capítulos 2 y 3, el objeto de estudio fueron índices de calidad biológica basados en peces y el espectro de tamaños de la comunidad ictiológica respectivamente. Para describir el régimen hidrológico, utilizamos un conjunto de variables calculadas a partir de series de caudal diarias y horarias facilitadas por la Confederación Hidrográfica del Ebro (CHE). Los resultados mostraron la importancia del caudal en la determinación de la composición ictiológica a nivel de especie, comunidad y estructura de tamaños. Estos conocimientos pueden ser de gran utilidad para el desarrollo de herramientas de restauración ecológica y conservación de especies de peces, especialmente en el contexto actual de crecientes presiones sobre los ecosistemas de agua dulce (calentamiento global, consumo de agua y especies invasoras, entre otras).Aquatic ecosystems are characterized by a strong coupling between physical forcing and ecological processes. In rivers, this physics-ecology interaction is driven by flow, one of the main factors determining biological integrity. The combination of high flow alterations due to dam regulation and an increasing presence of alien species is endangering native fish communities in the Iberian Peninsula. The aim of this thesis is to explore the relationships between flow regime and fish communities in the lower Ebro River by analysing data from electrofishing campaigns collected during more than 10 years. We addressed this objective through three different approaches: On Chapter 1, the relationships between single species abundances and hydrological regime were evaluated while in Chapter 2 and 3 the objects of study were fish-based biological quality indices and size spectrum of fish community, respectively. To describe flow regime, we used a set of hydrological variables calculated from daily and hourly flow data series provided by the Ebro Basin Water authority (Confederación Hidrográfica del Ebro). The results showed the importance of flow in shaping fish composition at species, community and size structure levels. This knowledge may prove useful for the development of ecological restoration tools and fish species conservation, especially in a context of increasing pressures over freshwater ecosystems (global warming, water consumption and invasive species, among others)

How Casa de la Camorra turned into the Cadiz Business School

Entre los usos del edificio conocido como la Casa de la Camorra, que se construyó a finales del siglo XVIII en la entonces calle Empedrador (actualmente Arbolí) de Cádiz, conocimos su ocupación como Escuela de Comercio entre los años 1906 y 1918. Los documentos generados por dicha Escuela actualmente se conservan en el Archivo de la Universidad de Cádiz que nos han aportado unas interesantes informaciones. Utilizamos para la investigación de manera preferente el contrato de arrendamiento del edificio y las actas del Claustro de Profesores de la Escuela.Among the uses of the building known as ‘Casa de la Camorra’, which was built during the late eighteen century in Emperador’s Street (currently named ‘Arbolí’) of Cádiz, we know its use as Business School between 1906 and 1918. The documents generated by this School are currently kept in the archive of the University of Cádiz, which have given us some interesting information. Preferably, we use for the research the leasing contract of the building and the proceedings of the Faculty

The behaviour of diborane-reduced fulvic acids in flash pyrolysis

7 pages, 3 figures, 1 table, 25 references.-- Publicado en el capítulo: Session 1: Isolation, Fractionation, and Characterization.-- Humic Substances in the Aquatic and Terrestrial Environment, Proceedings of an International Symposium, celebrado del 21-23, agosto, 1989 en Linköping, Suecia.-- Este volumen 33, referido en la Citación, consta de 514 páginas, 150 figuras y 57 tablas.It is suggested that the striking structural changes introduced in humic substances by reduction with diborane may be useful in studying the role of carboxyl groups in the behaviour of these substances in flash pyrolysis. In the preliminary results shown in this communication, pyrograms of two fulvic acids of different origins and the corresponding diborane reduced substances are compared. It was found that the diborane reduction was responsible for both qualitative and quantitative changes in the pyrolytic patterns of the fulvic acids. These patterns feflect the changes in the reactivity and structural stability of the fulvic materials caused by the disappearance of the carboxyl groups.Peer reviewe

Fulvic acids from particulate matter of a water-logged peatland

6 pages, 3 figures, 2 tables, 29 references.The presence of aggregates of humic substances (HS) with inorganic adsorbates in a lagoon located in Huelva (south Spain) is reported. The chemical nature of the fulvic acid (FA) fraction, extracted from the natural aggregate by treatment with chelating resins, has been investigated by physical and chemical methods. The results suggest that these FA are similar to FA from other aquatic environments. As revealed by FT-IR and NMR spectroscopies and mild oxidation with potassium persulfate, the FA contain predominantly in their structure polysaccharides and components derived from lignin.Peer Reviewe

EI Roc del Migdia (Vilanova de Sau,Osona): un jaciment mesolític atípic?

Peer reviewe

Analysis of the Cytisetea scopario-striati scrubs in the south-west-centre of the Iberian Peninsula

The statistical and phytosociological study of 255 relevés taken in the south-west of the Iberian Peninsula and made up of our own samples and previous publications reveals how close these relevés, previously ascribed to different syntaxa, really are. Our re-arrangement of the data leads us to propose for the territory the 15 associations already published and three new ones, namely: Genisto floridae-Adenocarpetum argyrophylli ass. nova hoc loco, Cytisetum bourgaei- eriocarpi nova, Lavandulo viridis-Cytisetum striati ass. nova hoc. loco. We also suggest a name correction, Adenocarpo anisochili-Cytisetum scoparii J.C. Costa et al. 2000 corr., and a status change, namely, Ulici latebracteati- Cytisetum striati (Costa et al. 2000) status novo

Melanins and lipids in Lycoperdon perlatum fruit bodies

5 pages, 1 figure, 3 tables, 27 references.After sequential degradation with sodium persulphate and potassium permanganate, the characteristics of the dark pigments from the soil gasteromycete Lycoperdonperlatum were described. Several aromatic acids (phenolic and benzenecarboxylic) were detected by glc-ms of the degradation products, but the aliphatic content of these polymer fractions was predominant, containing a high proportion of protein and showing fatty acids similar to those previously found in the lipid fraction. An acid soluble fraction of melanin, of a highly aliphatic nature, was also present in Lycoperdon fruit bodies.Peer reviewe

Las Relaciones Laborales. Un análisis institucional en base a la teoría de juegos evolutiva

Treballs Finals del Grau d'Economia, Facultat d'Economia i Empresa, Universitat de Barcelona, Curs: 2018-2019 , Tutor: Javier San Julián Arrupe(cast) El presente trabajo propone abordar un análisis de las relaciones laborales existentes en la economía contemporánea en base a las instituciones sociales que forman parte de cualquier interacción económica. Para ello se realizará una recopilación de las principales teorías y enfoques sobre la economía laboral, por un lado, y los marcos institucionales, por otro, a fin de construir un modelo que pueda ser congruente con la realidad observada y la literatura sobre la materia. A partir de dicho modelo se intentará analizar cómo varía a lo largo del tiempo el comportamiento estratégico de los agentes y su impacto en las variables relevantes.(eng) This paper aims to address an analysis of labour relations existing in the nowadays economy based on the social institutions that are part of any economic interaction. Especially we would look forward to understand how wages and the occupation rate are determined on an economy where decision making processes are decentralized. For this, a compilation of the main theories and approaches on labour economics, on the one hand, and institutional frameworks, on the other, will be carried out in order to build a model that could be consistent with the reality and the literature on the subject. We will try to analyse the main theories from a historical perspective, focusing on how the theoretical analysis has evolved through history. Starting from this model we will try to analyse how the strategic behaviour of the agents and their impact on the relevant variables varies over time. This analysis would be done through an a approach based on evolutionary game theory, a methodology originated in the natural sciences which has been used in some social studies because it allows researchers to introduce more realistic assumptions about human behaviour. Finally, a brief review of the proposed model would be made and the coherence of the results would be validated

Linking fish-based biological indicators with hydrological dynamics in a Mediterranean river: Relevance for environmental flow regimes

The relationship between flow dynamics and biological communities becomes especially relevant in Mediterranean rivers. Given their natural variability and growing anthropogenic pressures, their low sections are subjected to multiple impacts. The definition of ecohydrological relationships in Mediterranean rivers may constitute a useful management tool. Historically, fishes were the first group used to assess community-level ecological quality, and different indices and metrics have been proposed. However, up to date many of these indicators have showed to be insensitive to flow regime changes or hydrological alteration. There is therefore a need to deepen into the ecohydrological relationships between such indicators and flow regimes in Mediterranean (and other) rivers. This study presents an analysis of the relationship between interannual flow regimes in the lower section of the Ebro River, defined using a set of daily and hourly hydrological indices, and ecological quality based on fish community, assessed through indices designed to fulfill the Water Framework Directive (WFD) in Europe: the Indices of Biotic Integrity in Catalan rivers (IBICAT2010 and IBICAT2b) and the new European Fish Index (EFI+). In order to identify spatiotemporal patterns, hydrological indices were computed using time periods of different amplitude and ecological quality was obtained in different transects along the river section, even within the same water units or ‘water masses’ (subdivisions of surface waters to fulfill the WFD in Spain). Our results showed that IBICAT2010 was the most correlated with hydrological indices, followed by IBICAT2b and EFI+. The latter showed an almost null correlation with hydrological indices, which may be due to issues associated with the sampling technique, the definition of transects and because it does not uses stream typologies. Correlations among some hydrological and biological indices were observed, with temporal and spatial patterns. On one hand, daily hydrological indices showed relationship with ecological quality when they were computed using between 9 and 36 months of flow records (previous to the sampling date) whereas subdaily indices responded better to periods between 3 and 9 months of records. On the other hand, some sampling transects showed clearer relationships than others, even within the same water mass, which suggests an influence of hydromorphological variability on the obtained ecological quality scores.info:eu-repo/semantics/acceptedVersio