723 resultados para Fuego bacteriano
Resumo:
Usnea species of the Neuropogon group are amongst the most widespread and abundant macrolichens in Antarctic regions. Four principal species, U. antarctica, U. aurantiaco-atra, U. sphacelata and U. subantarctica, have been described on morphological grounds. However, identification to species level is often difficult and atypical morphologies frequently arise. Over 400 specimens were collected on the Antarctic Peninsula and Falkland Islands. Both morphological and molecular characters (ITS and RPB1) were used to compare samples to clarify taxonomic relationships. Morphological characteristics used included presence of apothecia, apothecial rays, soredia, papillae, fibrils, pigmentation and the diameter of the central axis as a proportion of branch diameter. Results revealed a very close relationship between U. antarctica and U. aurantiaco-atra, suggesting that they might constitute a species pair or be conspecific. Usnea sphacelata was comprised of at least two genetically distinct groups with no clear differences in morphology. One group included the first reported fertile specimen of this species. Usnea subantarctica was phylogenetically distinct from the other main Antarctic Usnea species, but clustered with U. trachycarpa. Genetic variation was evident within all species although there was no clear correlation between geographic origin and genetic relatedness. Phylogenetic analyses indicated that species circumscription in the Neuropogon group needs revision, with the principal species being non-monophyletic. None of the morphological characters, or groups of characters, used in this study proved to be completely unambiguous markers for a single species. However, axis thickness was supported as being informative for the identification of monophyletic lineages within the group.
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Chagas disease, caused by the parasite Trypanosoma cruzi, is the cause of Chronic chagasic cardiomyopathy (CCC). The prospection of innovative therapeutic agents against CCC is a major task. The recombinant form of 21 (rP21), a secreted T. cruzi protein involved in host cell invasion and on progression of chronic inflammatory processes have been studied as a potential novel therapeutic target. Our present work aimed to verify and investigate the impact of rP21 in the formation of blood vessels in vitro and in vivo. First, tEnd cells were treated with different concentrations of rP21 or bacterial extract and viability and cellular adhesion were evaluated by MTT and angiogenesis inhibition by Matrigel tube formation assay and murine model. To verify the proteolytic activity of rP21 on extracellular matrix (ECM) components, fibrinogen, matrigel and fibronectin was incubated with rP21 or not. In addition, we performed proliferation assays and cell cycle analysis. Furthermore, the accumulation and distribution of F-actin was determined by Phalloidin staining using ImageJ software. Finally, tEnd cells were incubated with rP21 and the mRNA levels were analyzed by real-time PCR. Our results showed that rP21 did not alter cell viability and adhesion, but strongly inhibited vessel formation in vitro and in vivo. Tube formation assay showed that angiogenesis inhibition was dependent of the CXCR4-rP21 binding. In addition to these results, we observed that the rP21 was able to inhibit cell proliferation and promoted a significant reduction in the number of 4n cells (G2/M phase). Moreover, we found that rP21 significantly increased F-actin levels and this protein was able to modulate expression of genes related to angiogenesis and actin cytoskeleton. However, rP21 showed no significant activity on the matrix components. In this sense, we conclude that the rP21-endothelial cells (ECs) interaction via CXCR4 promotes inhibition of vessel formation through a cascade of intracellular events, such as inhibition of ECs proliferation and modulation of the expression of molecules associated with angiogenic processes and actin cytoskeleton.
Resumo:
The dissertation was divided in two studies. With the first, aimed to evaluate the occurrence of microorganisms present in the vulvovaginal region of cows that received intravaginal progesterone devices during the fixed-time artificial insemination (FTAI) programs, and correlate the results with pregnancy rates. Samples were collected from vulvovaginal region of 30 beef cows Guzerá and 30 crossbred dairy cows, and also intravaginal devices, randomly. Of the 120 samples of cows, 60 corresponded to the collections of the period prior to the introduction device (D0) and 60 to the subsequent withdrawal of it (D9); it yielded 100% of bacterial growth, whereas, in most samples, it was found more than one isolated. In D0, the most frequent agent was Escherichia coli (52%), and in D9, Proteus spp and E. coli were the most frequent (32% and 28%, respectively). Regarding intravaginal progesterone devices, in D0 were isolated 37 microorganisms, being predominant those of the genus Bacillus (35%); in D9, 41 colony forming units (CFU) were isolated, of which 36.6% corresponded to Proteus spp. For the analysis of the antimicrobial profile, susceptibility testing was performed by diffusion agar disk, and cows that did not became pregnant after FTAI program were selected, as a future treatment. There resistance 100% to penicillin, and sensitivity, approximately, 90% to gentamicin, both isolates obtained from samples of beef cows and obtained of dairy cows. Regarding pregnancy rate, the 30 beef cows, 11 were diagnosed pregnant (36.7%), 4 (36.4%) treated with reused devices and 7 (63.6%) with new devices, which showed more effective. Of the 30 dairy cows, 15 were pregnant (50%), 8 (53.3%) were implanted with reused devices and 7 (46.7%) with new devices, with no significant differences in pregnancy rates. Because it is a research, females were chosen at random, and factors such as body condition, nutritional management and health weren't priority. With the second study, aimed to analyze the similarity between strains, conducted by technical Random Amplified Polymorphic DNA (RAPD -PCR). Presence of E. coli and the absence of pregnancy were selection criteria used. From the results, it was observed that most of the isolates wasn't phylogenetically similar, since they showed lower than 85% similarity. The study stressed the importance of E. coli in vulvovaginal microbiota of cows and the presence of phenotypic and genotypic characters of this bacterium on possible reproductive problems.
Resumo:
Las abejas, principalmente la especie Apis mellifera, desarrollan una función biológica muy importante puesto que se encargan de polinizar diversos cultivos agrícolas y la flora silvestre de todo el mundo. No obstante, existen numerosos factores que influyen en el estado sanitario de las colonias de abejas y presentan además un alto grado de interacciones entre ellos. Algunos de los potenciales riesgos para la apicultura española ya han sido identificados, como por ejemplo las dos especies de microsporidios, Nosema apis y N. ceranae, que actúan como parásitos intracelulares obligados o los ectoparásitos Varroa destructor, Acarapis woodi o Braula coeca; así como numerosos virus capaces de infectar a Apis melífera, de los cuales los principales son el virus de las alas deformadas (DWV), el virus de las realeras negras (BQCV), el virus Kashmir (KBV), el virus de la parálisis aguda (ABPV) y su variante israelí (IAPV). Otras enfermedades que afectan fundamentalmente a la cría de abejas son la loque americana y la loque europea, ambas de origen bacteriano (Paenibacillus larvae y Melissococcus plutonius respectivamente), así como la ascosferosis causada por el hongo Ascosphaera apis. Otro riesgo potencial para las abejas es la posible entrada de agentes exóticos como el coleóptero Aethina tumida o el ácaro Tropilaelaps clareae cuya presencia en Europa debe ser declarada según la OIE (2015). Recientemente se ha incluido a los neogregarinos y tripanosomátidos como posibles agentes patógenos. Actualmente, N. ceranae junto con V. destructor son los principales agentes patógenos que producen problemas sanitarios de las colonias de abejas en Europa. Además, se considera que los patógenos podrían jugar un papel primordial en el incremento de mortalidad de las abejas detectado en distintos países durante los últimos años...
Resumo:
This paper describes the composition and abundance of mesozooplankton of Bahi'a Ushuaia and Bahi'a Golondrina. These small bays are located in the northern Beagle Channel. Sampling was carried out from January 20 to 23, 2001 and samples were collected from the upper layer at nine stations. This study is the first research on mesozooplankton in this part of the Beagle Channel. Due to their dominance in the mesozooplankton community, we compared our Copepoda data with those reported by other authors from Antarctic coastal environments. By applying cluster analysis, we found two station groups in both bays: one in slightly polluted zones and the other in undisturbed external zones. Four assemblages in Bahi'a Ushuaia and two in Bahi'a Golondrina were determined by using non-metric multidimensional scaling (MDS) and cluster analysis. Mesozooplanktonic assemblages showed a certain resemblance in zones with and without anthropogenic influence. Most of the copepod species in our samples are typical of the sub-Antarctic region. Oithona similis (=0. helgolandica sensu Ramirez, 1966), Oncaea curvata, and Ctenocahmus citer show either similar or higher abundances at Antarctic coastal sites, including the upper layer in oceanic areas, in comparison with sub-Antarctic coastal localities. This suggests that, in agreement with other findings, the Polar Front is probably not a major geographic boundary for the distribution of these species.
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The shallow-water Asellota from the Beagle Channel were investigated, based on material collected at four localities in 2001-2002. A total of 3,124 asellotes were sorted, and three new species and 12 new records of distribution were reported. The Paramunnidae showed the highest species diversity and abundance (11 species and 1,463 specimens). The present research raises the number of species known from the Beagle Channel to 23; of these, 16 were previously reported from the Magellan Straits, representing 69% of similarity. Based on the present results and published data, the faunistic affinities for the shallow-water Asellota was 30% between the Magellan region and the Scotia Arc, and 26% between the Magellan region and the Antarctic Peninsula.
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Fossil associations from the middle and upper Eocene (Bartonian and Priabonian) sedimentary succession of the Pamplona Basin are described. This succession was accumulated in the western part of the South Pyrenean peripheral foreland basin and extends from deep-marine turbiditic (Ezkaba Sandstone Formation) to deltaic (Pamplona Marl, Ardanatz Sandstone and Ilundain Marl formations) and marginal marine deposits (Gendulain Formation). The micropalaeontological content is high. It is dominated by foraminifera, and common ostracods and other microfossils are also present. The fossil ichnoasssemblages include at least 23 ichnogenera and 28 ichnospecies indicative of Nereites, Cruziana, Glossifungites and ?Scoyenia-Mermia ichnofacies. Body macrofossils of 78 taxa corresponding to macroforaminifera, sponges, corals, bryozoans, brachiopods, annelids, molluscs, arthropods, echinoderms and vertebrates have been identified. Both the number of ichnotaxa and of species (e. g. bryozoans, molluscs and condrichthyans) may be considerably higher. Body fossil assemblages are comparable to those from the Eocene of the Nord Pyrenean area (Basque Coast), and also to those from the Eocene of the west-central and eastern part of South Pyrenean area (Aragon and Catalonia). At the European scale, the molluscs assemblages seem endemic from the Pyrenean area, although several Tethyan (Italy and Alps) and Northern elements (Paris basin and Normandy) have been recorded. Palaeontological data of studied sedimentary units fit well with the shallowing process that throughout the middle and late Eocene occurs in the area, according to the sedimentological and stratigraphical data.
Resumo:
This research presents Ludwig II of Baviera (1845-1886) as a historical figure and the vision of his reign theItalian director Luchino Visconti showed in his movies. This research states in an analytic and scrupulousway the relations between the historical figure, its filmic representation and the director himself. In addition,through an exhaustive research, this paper shows the aesthetics generated by directors like Visconti who reacheda remarkable peak in history of European film. Finally, this paper goes through the making of this film,which went from a transitional film within the Visconti oeuvre to one of his most troublesome and health-riskingprojects causing afterwards Visconti´s death.
Resumo:
This article analyses the context of production and local situations of appropriation and resignification related to the folk song “Fire on Animaná” as well as the request and mobilization (“The animanazo”) provoked by this song in order to examine different mechanisms and foundations by which a population connect with an event from its community past, identifying with this and taking it in a specific way. In this article we combine discourse analysis of the song and of interviews to participants in this event with the reconstruction —through ethnographic observation— of how to use this song.
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This article examines the institutional integration of activist art in the aftermath of the 2001 economic crisis in Argentina. Following this aim, we begin with a description of the most significant new groups of activist art in the City of Buenos Aires. Then, we elaborate the position these new groups take up in the field with respect to their dispute with the “light art” from the 90s, and in relation to the mutual accusations over the “trend” of political art. Finally, we analyse the reception of these groups of activist art in art exhibitions in the City of Buenos Aires and abroad, and we reflect upon the institutionalization of these specific and situated aesthetic and political practices.
Resumo:
This paper discusses some aspects of hunter-gatherer spatial organization in southern South Patagonia, in later times to 10,000 cal yr BP. Various methods of spatial analysis, elaborated with a Geographic Information System (GIS) were applied to the distributional pattern of archaeological sites with radiocarbon dates. The shift in the distributional pattern of chronological information was assessed in conjunction with other lines of evidence within a biogeographic framework. Accordingly, the varying degrees of occupation and integration of coastal and interior spaces in human spatial organization are explained in association with the adaptive strategies hunter-gatherers have used over time. Both are part of the same human response to changes in risk and uncertainty variability in the region in terms of resource availability and environmental dynamics.
Resumo:
La controversia ha acechado siempre a los museos, en especial, pero desde luego no de forma exclusiva, a aquellos museos de arte que exponen el arte moderno y contemporáneo. Probablemente siempre habrá controversias, ya que son ocasiones en las que el museo ha de enfrentarse directamente a un interrogatorio público sobre sus decisiones y procesos, a menudo demasiado ocultas y con frecuencia mal entendidas. Dado el creciente reconocimiento de que ya no es suficiente para los museos coleccionar, conservar y mostrar, sino más bien que los museos deben ahora comprometerse fundamental y directamente con sus comunidades, ¿cómo pueden los museos gestionar la controversia? ¿Pueden los museos aprender de la controversia para descubrir formas mejores de trabajar con sus públicos? Este artículo examinará tres controversias en los museos canadienses – Los cantos del espíritu, Voz de Fuego y Vanitas o El vestido de carne - en un intento de analizar estas preguntas usando los conceptos ANT de Bruno Latour.
Resumo:
El trabajo explica el vínculo existente entre las distintas concepciones platónicas del éros y de la poesía, como parte del legado poético del siglo v. Y analiza su evolución, y la de su relación con la filosofía, en Fedro, Banquete y República, como un proceso de destilación del éros elaborado por la poesía, del que es afín el éros filosófico configurado en el Fedro, pero cuya incompatibilidad, insinuada en el Banquete, se hace explícita y taxativa en la República. Todo ello con el fin de demostrar hasta qué punto asume el pensamiento de Platón la herencia poética precedente, poniendo en evidencia que dicho proceso responde, en todas sus fases, a un mismo objetivo: materializar el anhelo poético por excelencia: la creación de un «terreno intermedio» donde conciliar la irrenunciable dualidad de las aspiraciones humanas. En consecuencia, se invita aquí a mirar la ciudad platónica como materialización posible, no utópica, de un espacio logrado en el que integrar armónicamente la realidad y el deseo.
Resumo:
En El ciego de Quíos, el novelista Antonio Prieto inventa la vida de Homero alimentándola con figuras y hechos procedentes de la Ilíada y, sobre todo, de la Odisea. El relato se enriquece con el conocimiento histórico en torno a los dos grandes poemas, y lo enmarca un amplio despliegue mitológico. Más allá, la novela alcanza un significado trascendente. Descubrimos como motor narrativo el esfuerzo homérico por vencer la fugacidad humana mediante la escritura, lo que crea un vínculo atemporal con el propio anhelo de nuestro autor; así, la novela nos ofrece un ejemplo máximo del fenómeno bautizado como fusión mítica por Antonio Prieto.
Relaciones interétnicas en el Fuerte San José (Patagonia, siglo XVIII). Una aproximación comparativa
Resumo:
El presente trabajo tiene por objeto presentar la primera aproximación a las relaciones interétnicas en el escenario del Fuerte San José y el Puesto de la Fuente, desde una perspectiva histórica y arqueológica. En particular, presentaremos los primeros resultados de las investigaciones históricas respecto de la problemática mencionada, sobre la base de información inédita analizada hasta el momento. Para ello nos centraremos en los primeros diez años de vida en el Fuerte (1779-1789) y estableceremos una comparación con los otros dos asentamientos que formaron parte del plan de poblamiento español de las costa patagónica (siglo XVIII): el Fuerte Nuestra Señora del Carmen y la Nueva Colonia de Floridablanca, a los efectos de destacar la particularidad del Fuerte San José en el marco de la variabilidad de la estructuración de las relaciones interétnicas en las colonias patagónicas.