6,763 research outputs found

    Mauriac: The Ambivalent Author of Absence

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    This essay explores the significance of first- and third-person narrative voices. Although, as GĂ©rard Genette points out, the choice of either voice is not in itself significant, transitions between the two voices are. Such transitions serve to disclose the absence of an author\u27s point of view. They are a privileged means of revealing that no narrative voice can be entirely truthful or persuasive. In two Mauriac novels, ThĂ©rĂšse Desquevroux and Le Noeud de vipĂšres, transitions between first- and third-person voices are produced by linguistic differences between the I and the he. These differences create a rhetoric of voice: the he hides and figures an implicit I, while the I hides and figures an implicit he. This rhetoric generates opposing plots recounting both the author\u27s and the reader\u27s search for a hidden, truthful voice: for an implied writer or reader. One plot traces an effort to disclose, within an inauthentic he, a hidden, authentic I. It culminates only in a recognition of the formal nature of all stories and all voices that tell them. The other plot recounts the discovery that the I hides a he. It reveals a very different truth: that the I is alienated from its formal role and from the formal nature of the narratives it recounts. Both of these plots are linear accounts of how the narrative was composed and how it should be interpreted. Both create seemingly truthful voices—implied writers or readers—who tell them. But because these plots represent the same narrative in contradictory terms, they ultimately demonstrate the impossibility of saying what the narrative is doing or who, if anyone, is doing the narrating. Indeed, Mauriac\u27s characters ask whether the writing and reading of narrative do anything at all. Not only do they disclose the absence of an implied writer or reader; they call into question the very notion that the text represents or constitutes actions or events: its narrativity

    Influence of organic films on the evaporation and condensation of water in aerosol

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    Uncertainties in quantifying the kinetics of evaporation and condensation of water from atmospheric aerosol are a significant contributor to the uncertainty in predicting cloud droplet number and the indirect effect of aerosols on climate. The influence of aerosol particle surface composition, particularly the impact of surface active organic films, on the condensation and evaporation coefficients remains ambiguous. Here, we report measurements of the influence of organic films on the evaporation and condensation of water from aerosol particles. Significant reductions in the evaporation coefficient are shown to result when condensed films are formed by monolayers of long-chain alcohols [C(n)H((2n+1))OH], with the value decreasing from 2.4 × 10(−3) to 1.7 × 10(−5) as n increases from 12 to 17. Temperature-dependent measurements confirm that a condensed film of long-range order must be formed to suppress the evaporation coefficient below 0.05. The condensation of water on a droplet coated in a condensed film is shown to be fast, with strong coherence of the long-chain alcohol molecules leading to islanding as the water droplet grows, opening up broad areas of uncoated surface on which water can condense rapidly. We conclude that multicomponent composition of organic films on the surface of atmospheric aerosol particles is likely to preclude the formation of condensed films and that the kinetics of water condensation during the activation of aerosol to form cloud droplets is likely to remain rapid

    Size-resolved aerosol and cloud condensation nuclei (CCN) properties in the remote marine South China Sea - Part 1: Observations and source classification

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    Abstract. Ship-based measurements of aerosol and cloud condensation nuclei (CCN) properties are presented for 2 weeks of observations in remote marine regions of the South China Sea/East Sea during the southwestern monsoon (SWM) season. Smoke from extensive biomass burning throughout the Maritime Continent advected into this region during the SWM, where it was mixed with anthropogenic continental pollution and emissions from heavy shipping activities. Eight aerosol types were identified using a k-means cluster analysis with data from a size-resolved CCN characterization system. Interpretation of the clusters was supplemented by additional onboard aerosol and meteorological measurements, satellite, and model products for the region. A typical bimodal marine boundary layer background aerosol population was identified and observed mixing with accumulation mode aerosol from other sources, primarily smoke from fires in Borneo and Sumatra. Hygroscopicity was assessed using the Îș parameter and was found to average 0.40 for samples dominated by aged accumulation mode smoke; 0.65 for accumulation mode marine aerosol; 0.60 in an anthropogenic aerosol plume; and 0.22 during a short period that was characterized by elevated levels of volatile organic compounds not associated with biomass burning impacts. As a special subset of the background marine aerosol, clean air masses substantially scrubbed of particles were observed following heavy precipitation or the passage of squall lines, with changes in observed aerosol properties occurring on the order of minutes. Average CN number concentrations, size distributions, and Îș values are reported for each population type, along with CCN number concentrations for particles that activated at supersaturations between 0.14 and 0.85 %

    Decision-making without a brain: how an amoeboid organism solves the two-armed bandit

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    Several recent studies hint at shared patterns in decision-making between taxonomically distant organisms, yet few studies demonstrate and dissect mechanisms of decision-making in simpler organisms. We examine decision-making in the unicellular slime mould Physarum polycephalum using a classical decision problem adapted from human and animal decision-making studies: the two-armed bandit problem. This problem has previously only been used to study organisms with brains, yet here we demonstrate that a brainless unicellular organism compares the relative qualities of multiple options, integrates over repeated samplings to perform well in random environments, and combines information on reward frequency and magnitude in order to make correct and adaptive decisions. We extend our inquiry by using Bayesian model selection to determine the most likely algorithm used by the cell when making decisions. We deduce that this algorithm centres around a tendency to exploit environments in proportion to their reward experienced through past sampling. The algorithm is intermediate in computational complexity between simple, reactionary heuristics and calculation-intensive optimal performance algorithms, yet it has very good relative performance. Our study provides insight into ancestral mechanisms of decision-making and suggests that fundamental principles of decision-making, information processing and even cognition are shared among diverse biological systems

    Role of the Semi-lunar Process in Locust Jumping

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    We have developed a software toolkit, AnimatLab, which allows researchers to build and test virtual organisms. We used this software to build a virtual locust, and then asked how the semi-lunar process is utilized during jumping, and how manipulation or removal of the virtual SLP influences jump dynamics

    Experimental results for nulling the effective thermal expansion coefficient of fused silica fibres under a static stress

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    We have experimentally demonstrated that the effective thermal expansion coefficient of a fused silica fibre can be nulled by placing the fibre under a particular level of stress. Our technique involves heating the fibre and measuring how the fibre length changes with temperature as the stress on the fibre was systematically varied. This nulling of the effective thermal expansion coefficient should allow for the complete elimination of thermoelastic noise and is essential for allowing second generation gravitational wave detectors to reach their target sensitivity. To our knowledge this is the first time that the cancelation of the thermal expansion coefficient with stress has been experimentally observed

    Statistical thermodynamics unveils how ions influence an aqueous Diels-Alder reaction

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    The kinetics of Diels-Alder (DA) reactions in water has been known to be altered by salts for a long time. Yet the question how salts influence the reaction rate, either as rate-enhancing or rate-reducing additives, has so far remained unresolved. Conflicting hypotheses involve (i) indirect salt contributions through the modulation of internal pressure and (ii) making (or breaking) of the so-called “water-structure” by salts that strengthen (or weaken) the hydrophobic effect. In contrast to the qualitative nature of these hypotheses, here we answer this question quantitatively through a combination of transition state theory and fluctuation adsorption-solvation theory (FAST) using the DA reaction between anthracene-9-carbinol and N-ethylmaleimide as an example. We show that rate enhancement is driven by the salting out of the hydrophobic reagent, while rate-enhancing salts exhibit stronger affinity to the transition state
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