965 resultados para Lavigne, Alain
Resumo:
El autor interpreta el poemario Mordiendo el frío, del ecuatoriano Edwin Madrid. Lo hace a la luz de una afirmación del filósofo Alain Badiou: que el poema actual tiene solo una responsabilidad estética, ya no filosófica. Barreto afirma que Madrid muestra el deslinde entre filosofía y el poema moderno, para ello, se vale del lenguaje coloquial, el humor y la gozosa levedad sexual de Valerio, el personaje poético del libro. Según Barreto, el lenguaje poético, vacío, ya no cataliza la experiencia del sujeto: deviene en pura información. Añade que tal desconfianza en la poesía y el lenguaje líricos constituye una velada crítica a la institucionalización del género. Así, esta obra mostraría el agotamiento lírico de cierta poesía moderna. Barreto sugiere que dicho agotamiento se inserta en las condiciones globalizadas de las sociedades actuales, y que participa de la muerte de la experiencia en el sujeto moderno. Concluye que Madrid no lamenta la ruptura entre filosofía y poesía, por el contrario, busca trazar nuevas sensibilidades, signadas por la cotidianidad posmoderna.
Resumo:
The ability of four operational weather forecast models [ECMWF, Action de Recherche Petite Echelle Grande Echelle model (ARPEGE), Regional Atmospheric Climate Model (RACMO), and Met Office] to generate a cloud at the right location and time (the cloud frequency of occurrence) is assessed in the present paper using a two-year time series of observations collected by profiling ground-based active remote sensors (cloud radar and lidar) located at three different sites in western Europe (Cabauw. Netherlands; Chilbolton, United Kingdom; and Palaiseau, France). Particular attention is given to potential biases that may arise from instrumentation differences (especially sensitivity) from one site to another and intermittent sampling. In a second step the statistical properties of the cloud variables involved in most advanced cloud schemes of numerical weather forecast models (ice water content and cloud fraction) are characterized and compared with their counterparts in the models. The two years of observations are first considered as a whole in order to evaluate the accuracy of the statistical representation of the cloud variables in each model. It is shown that all models tend to produce too many high-level clouds, with too-high cloud fraction and ice water content. The midlevel and low-level cloud occurrence is also generally overestimated, with too-low cloud fraction but a correct ice water content. The dataset is then divided into seasons to evaluate the potential of the models to generate different cloud situations in response to different large-scale forcings. Strong variations in cloud occurrence are found in the observations from one season to the same season the following year as well as in the seasonal cycle. Overall, the model biases observed using the whole dataset are still found at seasonal scale, but the models generally manage to well reproduce the observed seasonal variations in cloud occurrence. Overall, models do not generate the same cloud fraction distributions and these distributions do not agree with the observations. Another general conclusion is that the use of continuous ground-based radar and lidar observations is definitely a powerful tool for evaluating model cloud schemes and for a responsive assessment of the benefit achieved by changing or tuning a model cloud
Resumo:
IR, UV-vis, and EPR spectroelectrochemistry at variable temperatures and in different solvents were applied to investigate in situ the formation of electroactive molecular chains with a nonbridged Os-Os backbone, in particular, the polymer [Os-0(bpy)(CO)(2)](n), (bpy = 2,2'-bipyridine), from a mononuclear Os(II) carbonyl precursor, [Os-II(bpy)(CO)(2)Cl-2]. The one-electron-reduced form, [Os-II(bpy(.-))(CO)(2)Cl-2](-), has been characterized spectroscopically at low temperatures. This radical anion is the key intermediate in the electrochemical propagation process responsible for the metal-metal bond formation. Unambiguous spectroscopic evidence has been gained also for the formation of [{Os-0(bpy(.-))(CO)(2)}(-)](n), the electron-rich electrocatalyst of CO2 reduction. The polymer species are fairly well soluble in butyronitrile, which is important for their potential utilization in nanoscience, for example, as conducting molecular wires. We have also shown that complete solubility is accomplished for the monocarbonyl-acetonitrile derivative of the polymer, [Os-0(bpy)(CO)(MeCN)(2)Cl](n).
Resumo:
Esta dissertação analisa os diálogos no Facebook, no perfil do Hemorio, o hemocentro do Estado do Rio de Janeiro, durante duas situações de crise, ambas no ano de 2011: as chuvas na Região Serrana do Rio de Janeiro e o ataque da Escola Municipal Tasso da Silveira, em Realengo. Embora estes períodos registrem aumento de mais de 400% nas doações de sangue voluntárias no Hemorio, não se buscou comprovar a \2018veracidade\2019 dos depoimentos ou mensurar a correlação entre as postagens e a doação efetiva. Nosso objetivo maior foi o de identificar os sentidos associados à doação de sangue, as motivações, as relações de troca e os sentimentos, tal como manifestos na mídia digital. Para alargar a compreensão do universo no qual o ato de doar está inscrito, utilizamos os estudos teóricos sobre a dádiva \2013 tanto o trabalho seminal de Marcel Mauss, o \201CEnsaio sobre a Dádiva\201D, como de autores contemporâneos, como Alain Caillé, Jacques Godbout, Paulo Henrique Martins e Alda Lacerda. Esta vertente foi conjugada com as teorias de redes sociais online (Henry Jenkins, Pierre Lévy, Mark Granovetter, Manuel Castells e Raquel Recuero), explorando as conexões entre a tríade \201Cdar, receber e retribuir\201D, como forma de estabelecer as relações sociais, e o universo digital
Resumo:
The gut microbiota enhances the host's metabolic capacity for processing nutrients and drugs and modulate the activities of multiple pathways in a variety of organ systems. We have probed the systemic metabolic adaptation to gut colonization for 20 days following exposure of axenic mice (n = 35) to a typical environmental microbial background using high-resolution (1)H nuclear magnetic resonance (NMR) spectroscopy to analyze urine, plasma, liver, kidney, and colon (5 time points) metabolic profiles. Acquisition of the gut microbiota was associated with rapid increase in body weight (4%) over the first 5 days of colonization with parallel changes in multiple pathways in all compartments analyzed. The colonization process stimulated glycogenesis in the liver prior to triggering increases in hepatic triglyceride synthesis. These changes were associated with modifications of hepatic Cyp8b1 expression and the subsequent alteration of bile acid metabolites, including taurocholate and tauromuricholate, which are essential regulators of lipid absorption. Expression and activity of major drug-metabolizing enzymes (Cyp3a11 and Cyp2c29) were also significantly stimulated. Remarkably, statistical modeling of the interactions between hepatic metabolic profiles and microbial composition analyzed by 16S rRNA gene pyrosequencing revealed strong associations of the Coriobacteriaceae family with both the hepatic triglyceride, glucose, and glycogen levels and the metabolism of xenobiotics. These data demonstrate the importance of microbial activity in metabolic phenotype development, indicating that microbiota manipulation is a useful tool for beneficially modulating xenobiotic metabolism and pharmacokinetics in personalized health care. IMPORTANCE: Gut bacteria have been associated with various essential biological functions in humans such as energy harvest and regulation of blood pressure. Furthermore, gut microbial colonization occurs after birth in parallel with other critical processes such as immune and cognitive development. Thus, it is essential to understand the bidirectional interaction between the host metabolism and its symbionts. Here, we describe the first evidence of an in vivo association between a family of bacteria and hepatic lipid metabolism. These results provide new insights into the fundamental mechanisms that regulate host-gut microbiota interactions and are thus of wide interest to microbiological, nutrition, metabolic, systems biology, and pharmaceutical research communities. This work will also contribute to developing novel strategies in the alteration of host-gut microbiota relationships which can in turn beneficially modulate the host metabolism.
Resumo:
Phthalates are industrial additives widely used as plasticizers. In addition to deleterious effects on male genital development, population studies have documented correlations between phthalates exposure and impacts on reproductive tract development and on the metabolic syndrome in male adults. In this work we investigated potential mechanisms underlying the impact of DEHP on adult mouse liver in vivo. A parallel analysis of hepatic transcript and metabolic profiles from adult mice exposed to varying DEHP doses was performed. Hepatic genes modulated by DEHP are predominantly PPARalpha targets. However, the induction of prototypic cytochrome P450 genes strongly supports the activation of additional NR pathways, including Constitutive Androstane Receptor (CAR). Integration of transcriptomic and metabonomic profiles revealed a correlation between the impacts of DEHP on genes and metabolites related to heme synthesis and to the Rev-erbalpha pathway that senses endogenous heme level. We further confirmed the combined impact of DEHP on the hepatic expression of Alas1, a critical enzyme in heme synthesis and on the expression of Rev-erbalpha target genes involved in the cellular clock and in energy metabolism. This work shows that DEHP interferes with hepatic CAR and Rev-erbalpha pathways which are both involved in the control of metabolism. The identification of these new hepatic pathways targeted by DEHP could contribute to metabolic and endocrine disruption associated with phthalate exposure. Gene expression profiles performed on microdissected testis territories displayed a differential responsiveness to DEHP. Altogether, this suggests that impacts of DEHP on adult organs, including testis, could be documented and deserve further investigations.
Resumo:
Accurate observations of cloud microphysical properties are needed for evaluating and improving the representation of cloud processes in climate models and better estimate of the Earth radiative budget. However, large differences are found in current cloud products retrieved from ground-based remote sensing measurements using various retrieval algorithms. Understanding the differences is an important step to address uncertainties in the cloud retrievals. In this study, an in-depth analysis of nine existing ground-based cloud retrievals using ARM remote sensing measurements is carried out. We place emphasis on boundary layer overcast clouds and high level ice clouds, which are the focus of many current retrieval development efforts due to their radiative importance and relatively simple structure. Large systematic discrepancies in cloud microphysical properties are found in these two types of clouds among the nine cloud retrieval products, particularly for the cloud liquid and ice particle effective radius. Note that the differences among some retrieval products are even larger than the prescribed uncertainties reported by the retrieval algorithm developers. It is shown that most of these large differences have their roots in the retrieval theoretical bases, assumptions, as well as input and constraint parameters. This study suggests the need to further validate current retrieval theories and assumptions and even the development of new retrieval algorithms with more observations under different cloud regimes.
Resumo:
A discussion of the taboo on nuclear use from the perspective of different governments, focusing on the circumstances of the post-Cold War environment where the danger of nuclear proliferation looms large.
Resumo:
A discussion of nuclear guarantees as means of deterrence and security projection in Europe, and also a countermeasure against nuclear proliferation. My contribution to this jointly authored book is contained mainly, but not exclusively, under the above section.