Search results for "Chen"
showing 10 items of 702 documents
Differences in the cell walls and extracellular polymers of the two Trebouxia microalgae coexisting in the lichen Ramalina farinacea are consistent w…
2015
Trebouxia TR1 and T. TR9 are the two microalgae that coexist within Ramalina farinacea thalli. In the presence of Pb, TR9 formed extracellular aggregates, while TR1 showed a lower wall lead retention capability. Herein, we studied the cell walls and extracellular polymers (EPS) of TR1 and TR9, and their possible implication in the different Pb retention capacity of these microalgae. The proportion of cell walls on the overall cell biomass was 2.6 times higher in TR9 than in TR1. Glycosyl linkage analysis indicated the presence of hot-water soluble β-galactofuranan(s) in both cell walls, distinct from that previously described in Asterochloris, with increased rhamnose content in TR9 and a hi…
Photosynthesis in Lichen: Light Reactions and Protective Mechanisms
2012
Lichens are symbiotic associations (holobionts) established between fungi (mycobionts) and certain groups of cyanobacteria or unicellular green algae (photobionts). This symbiotic association has been essential in establishing the colonization of terrestrial and consequently dry habitats. About 44 genera of algae and cyanobacteria have been reported as lichen photobionts. Due to the uncertain taxonomy of many of these photobionts, these numbers were considered as approximations only. Ahmadjian (1993) estimates that only 25 genera were typical lichen photobionts. The most common cyanobionts are Nostoc, Scytonema, Stigonema, Gloeocapsa, and Calothrix, in order of frequency (Budel, 1992). Gree…
Chloroplast morphology and pyrenoid ultrastructural analyses reappraise the diversity of the lichen phycobiont genus Trebouxia (Chlorophyta)
2022
Abstract Trebouxiophyceae is a wide class of green algae comprising coccoid and elliptic unicells, filaments, blades and colony-forming species that occur in diverse terrestrial and aquatic environments. Within this class, the genus Trebouxia Puymaly is among the most widespread lichen phycobionts worldwide. However, the 29 formally described species based on the combination of morphological traits and genetic diversity woefully underrepresented the overall species-level diversity recognized in the genus. In Trebouxia, reliable differentiation and characterization of the species-level lineages can be achieved by studying the diversity of key diagnostic features of pyrenoid ultrastructure an…
Preliminary assessment of terrestrial microalgae isolated from lichens as testing species for environmental monitoring: Lichen phycobionts present hi…
2013
Bioassays constitute a tool for pollution analysis providing a holistic approach and high-quality indication of the toxicity. Microbioassays allow evaluating the toxicity of many samples, implying lower costs and enabling routine monitoring and pollution control. But tests conducted so far are limited to the use of a small number of taxa. Lichens are excellent bioindicators of pollution with great ecological significance. Studies show that the phycobiont is more sensitive to pollutants than the mycobiont. Phycobiont have features such as adaptation to anhydrobiosis and relatively rapid growth in vitro, making them suitable for microbioassays. Our aim is to determine the sensitivity of phyco…
Two Trebouxia algae with different physiological performances are ever-present in lichen thalli of Ramalina farinacea. Coexistence versus Competition?
2010
This study was funded by the Spanish Ministry of Education and Science (CGL2006-12917-C02-01/02), the Spanish Ministry of Science and Innovation (CGL2009-13429-C02-01/02), the AECID (PCI_A/024755/09) and the Generalitat Valenciana (PROMETEO 174/2008 GVA). We are grateful to Dr J. Gimeno-Romeu (University of California, Davis, USA) and to Dr P. J. G. de Nova (IREC, Ciudad Real, Spain), who were the first to isolate DNA from Ramalina farinacea thalli in our group. Wendy Ran revised the manuscript in English.
Los caminos de la gobernanza, Expo Zaragoza 2008 España
2005
Am 16. Dezember 2004 wählte das Bureau international des expositions (B.I.E.) Spanien und seine Kandidatenstadt, die Metropole Saragossa, als Organisationsland für die nächste internationale Ausstellung „International Exhibition of Zaragoza Spain 2008: Water and Sustainable Development“. Wir analysieren zunächst die Entwicklung "der Wege" der Kandidaturen zur Wahl der Gastgeberstadt der Internationalen Ausstellung 2008, dann greifen wir in einem zweiten Mal den gesamten Vorgang der Ausarbeitung, Begründung und Durchführung der Internationalen Ausstellung 2008 in Saragossa auf im Kontext der Globalisierung neue städtische Formen und Formen des Regierens hervorbringen, indem alle finanziellen…
Lehrbuch der mandschurischen Sprache, Teil 1. Mandschurischer Text
1908
Violencia y género en la literatura de internado femenina en lengua alemana
2021
A principios del siglo XIX, la sociedad se expande a nivel demográfico, político e ideológico y en ella tiene lugar un cambio en los sistemas de poder. Las clases dominantes reclaman el control de los “campos sociales” con el fin de legitimar y perpetuar la integridad de las relaciones de desigualdad que las convierten en superiores. La naturaleza de las injusticias surge a través de la mutación de un castigo físico hacia una violencia simbólica, que asegura su perpetuación controlando el campo de la institución educativa. Esta situación prende la mecha social que permea en el ámbito de la literatura y representa al internado como fruto de las relaciones de poder. Mediante el estudio de la …
Distrofia Muscular de Duchenne y Becker: implicaciones cognitivas y conductuales
2021
La distrofia muscular de Duchenne (DMD; OMIM: 310200), es causada por la ausencia de distrofina; y la distrofia muscular de Becker (DMB; OMIM: 300376), es causada por una disminución o expresión anómala de distrofina. Al menos el 30% de los pacientes cursan con alteración cognitiva y conductual durante el neurodesarrollo. En esta investigación se pretenden estudiar los fenotipos cognitivos y conductuales asociados, en una muestra de pacientes españoles. Siendo el primer estudio cognitivo a nivel nacional. MÉTODO: 41 pacientes DMD, 19 pacientes DMB y 39 pacientes control. Rango de edades entre 3 y 16 años. Se valora el nivel cognitivo general del paciente (CI) y las funciones cognitivas espe…
Dracocephalum ruyschiana L. (Granstkalns pie Ikšķiles)
1901
Nordischer Drachenkopf finen in Livland, Kreis Riga. Grantkalns nordöstlich von Uexüll. /// Ruiša pūķgalve, atradne: Livlande, Rīgas apriņķī Granstkalnā ziemeļaustrumos no Ikšķiles. /// Northern Dragon-head, deposit: Livland, Riga district, Granstkalns, northeast of Ikšķile. [Attēls no LU Muzeja kolekcijas Herbarium Balticum (RIG I); (BOT 2791_1)]