987 resultados para Mancha de óleo no mar


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Chromosomally encoded systems involved in low level resistance of bacteria to different classes of antibiotics (mainly beta-lactams, chloramphenicol, quinolones and tetracycline), disinfectants and in resistance to organic solvents have been the focus of considerable interest in recent years. The multiple antibiotic resistance (mar) locus of Escherichia coli and Salmonella is perhaps the best described system involved in this type of resistance which is induced by MarA, the activator protein encoded by the marRAB locus. The mar-locus is reported to mediate resistance primarily by up-regulating efflux of some antibiotics, disinfectants and organic solvents via the AcrAB-TolC efflux pump and down regulating influx through Outer Membrane Protein F (OmpF). Whilst the level of antibiotic resistance conferred by marRAB is only low level, there are increasing data to suggest that marRAB and related systems are important in clinical antibiotic resistance, possibly as a 'stepping stone' to higher levels of resistance. Other related systems include up-regulation of RobA, SoxS and AcrAB which give rise to a similar resistance phenotype to that conferred by up-regulation of MarA. The aim of this paper is to review the function and significance of the mar-locus and related systems with a particular focus on its implications in veterinary medicine. (C) 2002 Published by Elsevier Science Ltd.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Recent studies of Michael Oakeshott have stressed the mutually constitutive importance of Hobbes to Oakeshott, arguing in part that Oakeshott’s Hobbes largely reflected his own concerns and broader philosophical project. This paper does not dispute this, but proposes a complementary account: Oakeshott’s interpretation of Hobbes was also formed in large measure by both his sympathy for Leo Strauss’s account and by his perception of it as the principal rival to his own. To demonstrate the existence of such a formative engagement, a close reading of Oakeshott’s essay The moral life in the writings of Thomas Hobbes is undertaken. Not only is Oakeshott found to have absorbed much of Strauss’s interpretation (surprisingly including Strauss’s distinction between esoteric and exoteric doctrines), the key impetus of the essay is shown to be a refutation of Strauss’s characterization of Hobbes as a ‘moralist of the common good’.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The Mar Menor is a coastal lagoon increasingly threatened by urban and agricultural pressures. The main watercourse draining into the lagoon is the Rambla del Albujón. A fortnightly campaign carried out over one annual cycle enabled us to characterize the treated urban sewage effluents and agricultural sources which contribute to the nutrient fluxes in the watercourse. Multivariate analysis provided information for establishing chemical signatures and for assessing the relative influence of the various sources on the water quality at the outlet. Mass balances were used to examine net gains and losses, and cross-correlations with rainfall to analyze climatic influence and control factors in the trends of the nutrient flux. The rainfall pattern was significantly cross-correlated with nitrate and phosphorus fluxes from agricultural sources, while fluctuations in the resident population explained the phosphorus flux trend in urban sources. 50% of dissolved inorganic nitrogen was from agricultural sources, while 70% of total phosphate and 91% of total organic carbon were from urban point sources. The net amounts of all the nutrients fell as a result of plant uptake and/or denitrification in the channel. The control of urban point sources (phosphorus-enriched) is suggested as a promptly action for improving the health of the coastal lagoon.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

1. Understanding the behaviour and ecology of large carnivores is becoming increasingly important as the list of endangered species grows, with felids such as Panthera leo in some locations heading dangerously close to extinction in the wild. In order to have more reliable and effective tools to understand animal behaviour, movement and diet, we need to develop novel, integrated approaches and effective techniques to capture a detailed profile of animal foraging and movement patterns. 2. Ecological studies have shown considerable interest in using stable isotope methods, both to investigate the nature of animal feeding habits, and to map their geographical location. However, recent work has suggested that stable isotope analyses of felid fur and bone is very complex and does not correlate directly with the isotopic composition of precipitation (and hence geographical location). 3. We present new data that suggest these previous findings may be atypical, and demonstrate that isotope analyses of Felidae are suitable for both evaluating dietary inputs and establishing geo-location as they have strong environmental referents to both food and water. These data provide new evidence of an important methodology that can be applied to the family Felidae for future research in ecology, conservation, wildlife forensics and archaeological science.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The Bocaina Plateau, which is situated on the eastern flank of the continental rift of southeastern Brazil, is the highest part of the Serra do Mar. Topographic relief in this area is suggested to be closely related to its complex tectono-magmatic evolution since the breakup of Western Gondwana and opening of the South Atlantic Ocean. Apatite fission track ages and track length distributions from 27 basement outcrops were determined to assess these hypotheses and reconstruct the denudation history of the Bocaina Plateau. The ages range between 303 +/- 32 and 46 +/- 5 Ma, and are significantly younger than the stratigraphic ages. Mean track lengths vary from 13.44 +/- 1.51 to 11.1 +/- 1.48 mu m, with standard deviations between 1.16 and 1.83 mu m. Contrasting ages within a single plateau and similar ages at different altitudes indicate a complex regional tectonothermal evolution. The thermal histories inferred from these data imply three periods of accelerated cooling related to the Early Cretaceous continental breakup, Early Cretaceous alkaline magmatism, and the Paleogene evolution of the continental rift of southeastern Brazil. The oldest fission track ages (>200 Ma) were obtained in the Serra do Mar region, suggesting that these areas were a long-lived source of sediments for the Parana, Bauru, and Santos basins. (C) 2010 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This essay is an analysis of the character María Josefa in the play 'The House of Bernarda Alba' (1936) by Federico García Lorca. It is hypothesized that the character of María Josefa can be considered a distorting mirror of the femininity presented in the play, and that through María Josefa this femininity is both revealed and problematized. The analysis adopts theories from the field of the (female) grotesque, using terminology both from Mikhail Bakhtin and Mary Russo. Throughout the analysis it is demonstrated how the character of María Josefa challenges the boundaries and norms which are dictated by Bernarda to control the women of the house. These conventions are challenged by María Josefa with the use of her loud speech, her dressed up appearance, and in her physical resistance. In this manner María Josefa is creating and embodying an alternate feminine view that is uncovered through her consistent provocation and by making herself into "a spectacle", a transboundary behaviour that is well interpreted within the theories of carnival, the grotesque body, and the spectacle of the female grotesque.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This essay poses a critical response to Strauss' political philosophy that takes as its primary object Strauss' philosophy of Law. It does this by drawing on recent theoretical work in psychoanalytic theory, conceived after Jacques Lacan as another, avowedly non-historicist theory of Law and its relation to eros. The paper has four parts. Part I, `The Philosopher's Desire: Making an Exception, or “The Thing Is...''', recounts Strauss' central account of the complex relationship between philosophy and `the city'. Strauss' Platonic conception of philosophy as the highest species of eros is stressed, which is that aspect of his work which brings it into striking proximity with the Lacanian-psychoanalytic account of the dialectic of desire and the Law. Part II, `Of Prophecy and Law', examines Strauss' analysis of Law as first presented in his 1935 book, Philosophy and Law, and central to his later `rebirth of classical political philosophy'. Part III, `Primordial Repression and Primitive Platonism', is the central part of the paper. Lacan's psychoanalytic understanding of Law is brought critically to bear upon Strauss' philosophy of Law. The stake of the position is ultimately how, for Lacanian psychoanalysis, the Law is transcendental to subjectivity, and has a founding symbolic force, which mitigates against speaking of it solely or primarily in terms of more or less inequitable `rules of thumb', as Plato did. Part IV, `Is the Law the Thing?' then asks the question of what eros might underlie Strauss' paradoxical defense of esoteric writing in the age of `permissive' modern liberalism - that is, outside of the `closed' social conditions which he, above all, alerts us to as the decisive justification for this ancient practice.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Rumors surrounding the Hebraic-American classical philosopher Leo Strauss’ supposed influence on leading neoconservative politicians and commentators make reconsidering Leo Strauss’ thought and legacy a philosophical task of the first political importance today. A host of articles have appeared by students and (more recently) books by Stephen Smith (2006), Heinrich Meier (2006) and Catherine and Michael Zuckert (2006). This essay is proffered as a critical contribution, by a non-Straussian student, to this literature. Its methodology and justification is to return to and reconsider Strauss’ earliest works, on the ‘political theology’ of Benedict de Spinoza. The paper argues two theses. The first is that the popular depiction of Strauss as an esoteric Nietzschean hiding behind a ‘noble’ classical or theological veneer importantly misses the mark. The second is that Strauss’ early work shows his proximity, via Jacobi, to the Heideggerian disclosure of the groundless grounds of philosophical reason, given which one must extra-rationally choose reason over faith. One striking implication of this argument, in the contemporary political climate, is to underscore the unlikely convergence between the philosophical sources of neoconservative and the ‘post-structuralist’ thought associated with much of the intellectual left in France and the Anglophone world. Yet in contrast to the widespread image of Strauss, I argue that the mature Strauss’ continuing commitment to this decisionistic framework is in fact most clear is his ‘exoteric,’ public statements on religion – i.e. it is not the ‘esoteric’ purloined letter Strauss’ critics seek out. The reason for Strauss’ continuing public advocacy of the impossibility of reason’s disproving faith, I propose, highlights the primarily political (versus philosophical) nature of this turn: in Strauss’ conservative acceptance of the political necessity of religion for social order, framed in terms of a revised commitment to the ‘medieval’ (versus modern) enlightenment of Maimonides and Farabi.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this paper we study the problem of routing in opportunistic wireless network, and propose a novel routing mechanism, message-aware routing (MAR). Using MAR, the messages can be prioritized at mobile nodes and the resources will be allocated accordingly. The MAR uses the message-aware socializing model to classify mobile nodes into different social groups. In MAR, nodes only maintain up-to-date routing information for the nodes in the same social group and the messages for the nodes in the same social group will have higher priority to be delivered. The MAR improves the routing efficiency in terms of reduced traffic and a higher delivery success rate. Further, MAR is constructed in decentralized way and does not require any centralized infrastructure. Experiments using NS2 simulator show that the MAR achieves higher delivery rate than the Epidemic and Prophet routing.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Marketing Principles. by Craig Walters and Leo-Paul Dana. 4th ed. Pearson Prentice Hall, 2007. 576pp. ISBN: 1-87737-137-8

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Phosphorylated sperm proteins are crucial for sperm maturation and capacitation as a priori to their fertilization with eggs. In the freshwater prawn, Macrobrachium rosenbergii, a male reproduction-related protein (Mar-Mrr) was known to be expressed only in the spermatic ducts as a protein with putative phosphorylation and may be involved in sperm capacitation in this species. We investigated further the temporal and spatial expression of the Mar-Mrr gene using RT-PCR and in situ hybridization and the characteristics and fate of the protein using immunblotting and immunocytochemistry. The Mar-Mrr gene was first expressed in 4-week-old post larvae and the protein was produced in epithelial cells lining the spermatic ducts, at the highest level in the proximal region and decreased in the middle and distal parts. The native protein had a MW of 17 kDa and a high degree of serine/threonine phosphorylation. It was transferred from the epithelial cells to become a major protein at the anterior region of the sperm. We suggest that it is involved in sperm capacitation and fertilization in this open thelycal species and this is being investigated.