Fitoplancton de dos lagunas de los humedalesde Xeresa y Xeraco (Valencia, España).

VILLENA, M. J. & ROMO, S. 2001. Fitoplancton de dos lagunas de los humedales de Xeresa y Xeraco (Valencia, España). Bot. Complutensis 25: 179-189. Se ha estudiado la composición fitoplanctónica de dos lagunas costeras mediterráneas, que corresponden a los marjales de Xeresa y Xeraco (Valencia). Estas zonas húmedas de la Comunidad Valenciana poseen un importante valor ecológico y botánico para nuestra Península, aunque actualmente se encuentran amenazadas por transformaciones de tipo turístico o agrícola. Las lagunas estudiadas se caracterizan por ser someras (Zmax: 3 m), oligohalinas, de aguas transparentes y mesotróficas, y por encontrarse sobre lechos de turba y con praderas de macrófitos sumergidos. El fitoplancton observado destaca por presentar una composición similar para ambas lagunas, con especies cosmopolitas y abundancia de microalgales de pequeño tamaño. Esta estructura de tamaño resulta importante para mantener las complejas redes tróficas de estos lagos someros. El grupo algal más diverso, en ambas lagunas, fue el de las clorofíceas. Sin embargo, la abundancia y biomasa algal fue acaparada por las cianofíceas filamentosas en la laguna de Xeresa, mientras que las clorofíceas y criptofíceas dominaron en la laguna de Cap de Terme.VILLENA, M. J. & ROMO, S. 2001. Phytoplankton from two lakes of Xeresa and Xeraco wetlands (Valencia, Spain). Bot. Complutensis 25: 179-189. Phytoplankton composition from two Mediterranean Coastal lakes located in Xeresa and Xeraco wetlands (Valencia, Spain) were studied. These wetlands from the Comunidad Valenciana have an important ecological and botanical value for the Iberian Peninsula, although nowadays they are threatened by turistic and agriculture development. The study lakes are characterized to be shallow (Zmax: 3 m), oligohaline, water transparent, mesotrophic and peat lakes, which are covered by sumerged macrophytes. The phytoplankton observed was similar in both lakes, with cosmopolitan species and abundant small-size microalgae. This size structure is relevant for the maintenance of the complex food-webs of these shallow la 179 M. J. Villena & S. Romo Fitoplancton de dos lagunas de los humedales de Xeresa... kes. The most diverse algal group, in both study lakes, corresponded to chlorophytes. However, the algal abundance and biomasa was overwhelmed by cyanophytes in the lake of Xeresa, but by chlorophytes and cryptophytes in the lake of Cap de Terme

Dipper-Donkin algebra as global symmetry of quantum chains

We analize the role of GL_2, a quantum group constructed by Dipper-Donkin, as a global symmetry for quantum chains, and show the way to construct all possible Hamiltonians for four states quantum chains with GL_2 global symmetry. In doing this, we search all inner actions of GL_2 on the Clifford algebra C(1,3) and show them. We also introduce the corresponding operator algebras, invariants and Hamiltonians, explicitly.Comment: 30 pages, 3 Figures, LaTex2

A Fresh Look at Huntingtin mRNA Processing in Huntington\u27s Disease

Huntington\u27s disease (HD) is an inherited neurodegenerative disorder caused by a mutation that expands the polyglutamine (CAG) repeat in exon 1 of the huntingtin (HTT) gene. Wild-type HTT protein interacts with other proteins to protect cells against toxic stimuli, mediate vesicle transport and endocytosis, and modulate synaptic activity. Mutant HTT protein disrupts autophagy, vesicle transport, neurotransmitter signaling, and mitochondrial function. Although many of the activities of wild-type HTT protein and the toxicities of mutant HTT protein are characterized, less is known about the activities of HTT mRNA. Most putative HD therapies aim to target mutant HTT mRNA before it is translated into the protein. Therefore, it is imperative to learn as much as we can about how cells handle both wild-type and mutant HTT mRNA so that effective therapies can be designed. Here, we review the structure of wild-type and mutant HTT mRNA, with emphasis on their alternatively polyadenylated or spliced isoforms. We then consider the abundance of HTT mRNA isoforms in HD and discuss the potential implications of these findings. Evidence in the review should be used to guide future research aimed at developing mRNA-lowering therapies for HD

How agriculture, connectivity and water management can affect water quality of a Mediterranean coastal wetland

The Natural Park of Albufera (Valencia, Spain) is an important Mediterranean coastal wetland that suffers continuous environmental effects from human activities and water uses, mainly related to agriculture and urban/industrial sewage discharges. The aim of this research was to assess the water quality of the different aquatic environments of this wetland, taking into account the connection between them, the agricultural impact and the management of irrigation water. The UEWater Framework Directive was followed in order to evaluate the ecological and trophic status of water systems. Spatial approaches were used to integrate physicochemical data into GIS vector layers to map the more problematic points of pollution. The results showed a globally eutrophic system with poor ecological potential. The wetland is nutrient-overloaded during the entire rice cultivation period. Good-quality water inputs are deficient, since the river network already has high levels of nutrients and pollutants, especially in the northern area, where river water is mixed with inappropriate effluents from wastewater treatment plants. Agriculture and water management affected the area intensively up to the Albufera lake, modulating most of the studied variables. The information gathered here can help to optimize the global study and management of the coastal Mediterranean wetlands, which are highly linked to agriculture

Examples of q-regularization

An Introduction to Hopf algebras as a tool for the regularization of relavent quantities in quantum field theory is given. We deform algebraic spaces by introducing q as a regulator of a non-commutative and non-cocommutative Hopf algebra. Relevant quantities are finite provided q\neq 1 and diverge in the limit q\rightarrow 1. We discuss q-regularization on different q-deformed spaces for \lambda\phi^4 theory as example to illustrate the idea.Comment: 17 pages, LaTex, to be published in IJTP 1995.1