Flora liquènica epifítica de la Punta de la Mora (Tarragonès, Catalunya)

Hom presenta el catàleg florístic dels líquens epífits del savinar litoral de la punta de la Mora, localitat d'excepcional interès florístic, biogeogràfic i fitosociològic, tant pel que fa a la vegetació vascular com a la liquènica. Hom ha trobat un total de 74 tàxons en una àrea de només 400 Ha, nombre força elevat en comparació amb moltes altres localitats del litoral tarragoní recentment estudiades. Per a cadascun dels tàxons, hom indica la seva ecologia i, en alguns casos, les citations s'acompanyen amb descriptions abreujades i iconografia. Entre les espècies més notables cal destacar: B. Ignarii (Nyl.) Oxner, B. Subacerina Vain., Biatorella ochrophora (Nyl.) Am., B. aff. Laricina (Stein.) D. Hawksw. et Eriks., Buellia schaereri DN., Hypocenomyce stoechadiana Abassi Maaf et Roux, Leptorhaphis oleae (Massal.) Koerber, Melaspilea proximella Nyl., Micarea synotheoides (Nyl.) Coppins and Pyrenula chlorospila (Nyl.) Arn.Floristic results of a survey devoted to lichen epiphytes of the sabine and pine coastal woods of Punta de la Mora, a relict representative of west Mediterranean coastal vegetation. In the surveyed area (400 Ha), 74 epiphytic taxa have been recognized, a figure higher than those of other localities studied in the coast of Tarragona. Data on ecology and distribution are complemented, in some cases, with descriptions and iconography. Some species are worthy of being pointed out: Bacidia ignarii (Nyl.) Oxner, B. subacerina Vain., Biatorella ochrophora (Nyl.) Am., B. aff laricina (Stein.) D. Hawksw. et Eriks., Buellia schaereri DN., Hypocenomyce stoechadiana Abassi Maaf et Roux, Leptorhaphis oleae (Massal.) Koerber, Melaspilea proximella Nyl., Micarea synotheoides (Nyl.) Coppins and Pyrenula chlorospila (Nyl.) Arn

Flora i vegetació liquènica nitròfila del Delta de l'Ebre

S'ofereix la llista dels tàxons, líquens i jongs liquenicoles, observats sobre els substrats rocosos, construccions d'utilitat agrícola, i sobre els diferents foròfits existents al delta de l'Ebre. Entre els tàxons que constitueixen nova citació o són interessants per a la flora de Catalunya es poden destacar Caloplaca ulcerosa, Lecania cyrtellinoides, Lecanora hybocarpa, Polyblastiopsis lactea i Thelenella modesta entre els epifítics, i Collemopsis schaereri, Lecanora lisbonensis, Thelidium olivaceum, Verrucaria macrostoma i V. ochrostoma entre els saxícoles. S'inclou un esbòs fitosociològic, amb un comentari de les principals comunitats liquèniques observades. Les comunitats epifítiques s'inclouen en l'aliança Lecanorion subfuscae, i les saxícoles en l'aliança Caloplacion decipientis. En general, es pot considerar la flora i la vegetació liquènica de l'àrea com a fortament nitròfila, molt influïida per l'acció de l'home, sobretot a causa dels tractaments agrícoles que sofreix el delta de l'Ebre.A list is afforded of the taxa, lichens and lichenicolons jungi, observed on non-living substrates (mainly on agricole constructions) and on the main trees and shrubs growing in the Ebro Delta, in a region of fairly mild winters. A good number of the taxa are new or interesting records for the Catalan flora. Amongst them, Caloplaca ulcerosa, Lecania cyrtellinoides, Lecanora hybocarpa, Polyblastiopsis lactea and Thelenella modesta as epiphytic, and Collemopsis schaereri, Lecanora lisbonensis, Thelidium olivaceum, Verrucaria macrostoma and V. ochrostoma as saxicolous. Also included is a phytosociological draft of the main observed lichen communities. Epiphytic ones belong to the Al. Lecanorion subfuscae; saxicole ones, to the Al. Caloplacion decipientis, with rather original species composition. The lichen flora and vegetation of this deltaic plain can be mainly considered as neatly nitrophilous, because of man influence, through intense agricultural exploitation

An Update on Autophagy in Prion Diseases

Autophagy is a dynamic intracellular mechanism involved in protein and organelle turnover through lysosomal degradation. When properly regulated, autophagy supports normal cellular and developmental processes, whereas defects in autophagic degradation have been associated with several pathologies, including prion diseases. Prion diseases, or transmissible spongiform encephalopathies (TSE), are a group of fatal neurodegenerative disorders characterized by the accumulation of the pathological misfolded isoform (PrPSc) of the physiological cellular prion protein (PrPc) in the central nervous system. Autophagic vacuoles have been described in experimental models of TSE and in the natural disease in humans. The precise connection of this process with prion-related neuropathology, or even whether autophagy is completely beneficial or pathogenic during neurodegeneration, is poorly understood. Thus, the biological role of autophagy in these diseases is still open to debate. During the last years, researchers have used a wide range of morphological, genetic and biochemical methods to monitor and manipulate the autophagic pathway and thus determine the specific role of this process in TSE. It has been suggested that PrPc could play a crucial role in modulating the autophagic pathway in neuronal cells, and the presence of abnormal autophagic activity has been frequently observed in several models of TSE both in vitro and in vivo, as well as in human prion diseases. Altogether, these findings suggest that autophagy is implicated in prion neuropathology and points to an impairment or failure of the process, potentially contributing to the pathogenesis of the disease. Additionally, autophagy is now emerging as a host defense response in controlling prion infection that plays a protective role by facilitating the clearance of aggregation-prone proteins accumulated within neurons. Since autophagy is one of the pathways of PrPSc degradation, and drug-induced stimulation of autophagic flux (the dynamic process of autophagic degradation activity) produces anti-prion effects, new treatments based on its activation have been tested to develop therapeutic strategies for prion diseases. In this review, we summarize previous and recent findings concerning the role of autophagy in TSE

Stigmatella aurantiaca, un mixobacteri amb aspecte de mixomicet, trobat al Parc de Collserola (Catalunya)

Stigmatella allrantiaca, un mixobacteri amb aspecte de mixomicet, trobat al Parc de Collserola (Catalunya). Stigmatella aurantiaca ha estat trobada sobre restes vegetals recol·lectades a Collserola, prop de Barcelona (Catalunya). Es tracta d'un mixobacteri que rarament es pot veure formant cossos fructífers a la natura i es pot confondre fàcilment amb un mixomicet immadur. Forma grups de cossos fructífers molt petits, de color taronja, portats per pedicels blancs.Stigmatella allrantiaca, a myxomycete-looking myxobacterium, found in Collserola Park (Catalonia). Stigmatella aurantiaca has been found on plant debris collected in ColIserola, near Barcelona (Catalonia). It belongs to myxobacteria, a group of procariotes rarely found fonuing fruiting bodies in the nature, where it may easily be confused with an immature myxomycete. It forms clusters of tiny fruiting bodies, orange coloured, on white stalks.Stigmatella aurantiaca, una mixobacteria con aspecto de mixomicete, hallada en el Parque de Collserola (Cataluña). Stigmatella aurantiaca ha sido encontrada sobre restos vegetales recolectados en Collserola, cerca de Barcelona (Cataluña). Se trata de una mixobacteria que raramente se puede ver formando cuerpos fructíferos en la naturaleza y que fácilmente se puede confundir con algún mixomicete inmaduro. Forma grupos de diminutos cuerpos fructíferos de color naranja, sostenidos por pedicelos blancos

Silver nanoparticles-clays nanocomposites as feed additives: Characterization of silver species released during in vitro digestions. Effects on silver retention in pigs

Two different clay nanocomposites, as sepiolite-Ag and kaolinite-Ag, are studied as carriers for silver nano particles (AgNPs) oral administration as antimicrobial agent in additives for animal feed. A three-step digestibility assay, corresponding to stomach, small and large intestine simulations, has been followed. Ultrafiltration and asymmetrical flow field-flow fractionation (AF4) coupled to UV-Vis absorption and ICPMS detectors have been used for size characterisation of the silver species released during the in vitro digestibility assays. Less than 1% of the total silver is released in the stomach simulation step, probably due to the formation of silver chloride on the nanocomposite surface. In the case of the intestine simulation, silver released increases and tends to form complexes with the enzymes present in the media. A larger amount of silver was released from kaolinite-Ag compared to sepiolite-Ag (17 vs. 7%), probably due to a higher retention rate of silver shown by sepiolite, justified by its sorption capacity and fibrous structure. No evidences were found about a significant release of silver nanoparticles along the in vitro assay from any of the two nanocomposites studied. These results have been compared to the silver levels found in liver and faeces from weaned pigs fed with these supplements for 35 days and followed by basal diet free of silver for 4 weeks in an in vivo assay. Piglets fed with kaolinite-Ag retained more silver in liver than those receiving sepiolite-Ag, and the opposite was observed in faeces, although differences were not statistically significant. Silver levels found in muscles were below the limit of detection (0.009 mu g Ag g(-1)) in all cases

Stigmatella aurantiaca, un mixobacteri amb aspecte de mixomicet, trobat al Parc de Collserola (Catalunya)

Stigmatella allrantiaca, un mixobacteri amb aspecte de mixomicet, trobat al Parc de Collserola (Catalunya). Stigmatella aurantiaca ha estat trobada sobre restes vegetals recol·lectades a Collserola, prop de Barcelona (Catalunya). Es tracta d'un mixobacteri que rarament es pot veure formant cossos fructífers a la natura i es pot confondre fàcilment amb un mixomicet immadur. Forma grups de cossos fructífers molt petits, de color taronja, portats per pedicels blancs.Stigmatella aurantiaca, una mixobacteria con aspecto de mixomicete, hallada en el Parque de Collserola (Cataluña). Stigmatella aurantiaca ha sido encontrada sobre restos vegetales recolectados en Collserola, cerca de Barcelona (Cataluña). Se trata de una mixobacteria que raramente se puede ver formando cuerpos fructíferos en la naturaleza y que fácilmente se puede confundir con algún mixomicete inmaduro. Forma grupos de diminutos cuerpos fructíferos de color naranja, sostenidos por pedicelos blancos.Stigmatella allrantiaca, a myxomycete-looking myxobacterium, found in Collserola Park (Catalonia). Stigmatella aurantiaca has been found on plant debris collected in ColIserola, near Barcelona (Catalonia). It belongs to myxobacteria, a group of procariotes rarely found fonuing fruiting bodies in the nature, where it may easily be confused with an immature myxomycete. It forms clusters of tiny fruiting bodies, orange coloured, on white stalks

A comparison of microsecond vs. millisecond dwell times on particle number concentration measurements by single particle ICPMS

With the growing popularity of nanomaterials in a wide variety of products and processes, the need to measure and characterize these materials has also grown. For metallic or metal-containing engineered nanoparticles (NPs), single particle ICP-MS (SP-ICP-MS) has been developed and is growing in popularity due to its ability to rapidly detect and characterize a large number of particles, determine particle size and size distributions, the particle number concentration in a sample, and the elemental mass concentration of both dissolved and particulate species. SP-ICP-MS has been applied to a wide variety of sample types1-5, demonstrating its versatility. A key variable in SP-ICP-MS, which must be applied correctly for accurate measurement of particle concentration, is the dwell time of the ICP-MS. Although this topic has been discussed previously6,7, this work will focus on direct comparisons of results using both microsecond and millisecond dwell times. Since a detailed version of this work is available8, only a brief description will be given here

Establishment of a network of monitoring stations using lichens as indicators. Base for the assessment of human impact and air quality on the vegetation in the Aigüestortes i Estany de Sant Maurici National Park

Com a primera part de la monitorització, mitjançant el líquens com a indicadors, del Parc Nacional d’Aigüestortes i Estany de Sant Maurici, hem seleccionat, marcat i caracteritzat 20 estacions de seguiment. Les estacions han quedat establertes en els següents ambients: rouredes amb boix, bosc caducifoli mixt, fagedes, fagedes amb avet, pinedes de pi roig, avetosa, avetosa amb neret, pinedes de pi negre amb neret o amb ginebró, i roquissars, tant en roques carbonatades com àcides. Donem, com a exemple de l’estudi d’aquestes estacions, el cas d’una estació establerta a la comunita d’avetosa amb neret. El seguiment de l’evolució, en el temps, de les diferents comunitats, ens haurà de permetre correlacionar les modificacions observades en les estacions amb els canvis produïts en la qualitat de l’aire o a causa de l’impacte humà.As a first part of the monitoring project, using lichens as indicators of the Aigüestortes and Estany de Sant Maurici National Park, 20 monitoring stations have been selected, marked and characterised. The stations were included in the following plant communities: Buxo-Quercetum pubescentis, Helleboro-Fagetum, Luzulo-Fagetum, Hylocomio- Pinetum catalaunicae, Goodyero-Abietetum, Saxifrago-Rhododendretum abietetosum albae, Saxifrago-Rhododendretum pinetosum uncinatae and Arctostaphylo-Pinetum uncinatae, and in rocky places on carbonated and siliceous rocks. As an example of study of these stations, we give the information of one station located in Saxifrago- Rhododendretum abietetosum albae. The changes of the different communities through time allow us to correlate these observed modifications with changes in the air quality or due to the human impact