969 resultados para word-formation processes


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The word 'palaver' is colloquially associated with useless verbiage and the nuisance of a tediously long, aimless and superfluous debate. At the same time, it insinuates an uncivilized culture of discourse beyond reason. Thus it appears to be of vaguely exotic origin but still firmly set in the European lexicon. Yet behind this contemporary meaning there lies a long history of linguistic and cultural transfers which is encased in a context of different usages of language and their intersections. By tracing the usage and semantics of 'palaver' in various encyclopaedias, glossaries and dictionaries of English, French, German, Portuguese and Spanish, the following article explores the rich history of this word. Moreover, it also regards the travelling semantics of the term 'palaver' as a process of cultural transfer that can be likened to the microcellular workings of a (retro)virus. Viral reproduction and evolution work through processes of transfer that enable the alteration of the host to adjust it to the replication and reproduction of the virus. In some cases, these processes also allow for the mutation or modification of the virus, making it suitable for transfer from one host to another. The virus is thus offered here as a vital model for cultural transfer: It not only encompasses the necessary adoption and adaption of contents or objects of cultural transfer in different contexts. It contributes to a conceptual understanding of the transferal residue that the transferred content is endowed with by its diversifying contexts. This model thereby surpasses an understanding of cultural transfer as literal translation or transmission: it conceptualizes cultural transfer as an agent of evolutionary processes, allowing for mutational effects of transfer as endowment.

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Why do people take longer to associate the word “love” with outgroup words (incongruent condition) than with ingroup words (congruent condition)? Despite the widespread use of the implicit association test (IAT), it has remained unclear whether this IAT effect is due to additional mental processes in the incongruent condition, or due to longer duration of the same processes. Here, we addressed this previously insoluble issue by assessing the spatiotemporal evolution of brain electrical activity in 83 participants. From stimulus presentation until response production, we identified seven processes. Crucially, all seven processes occurred in the same temporal sequence in both conditions, but participants needed more time to perform one early occurring process (perceptual processing) and one late occurring process (implementing cognitive control to select the motor response) in the incongruent compared with the congruent condition. We also found that the latter process contributed to individual differences in implicit bias. These results advance understanding of the neural mechanics of response time differences in the IAT: They speak against theories that explain the IAT effect as due to additional processes in the incongruent condition and speak in favor of theories that assume a longer duration of specific processes in the incongruent condition. More broadly, our data analysis approach illustrates the potential of electrical neuroimaging to illuminate the temporal organization of mental processes involved in social cognition.

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The bulk magnetic mineral record from Lake Ohrid, spanning the past 637 kyr, reflects large-scale shifts in hydrological conditions, and, superimposed, a strong signal of environmental conditions on glacial–interglacial and millennial timescales. A shift in the formation of early diagenetic ferrimagnetic iron sulfides to siderites is observed around 320 ka. This change is probably associated with variable availability of sulfide in the pore water. We propose that sulfate concentrations were significantly higher before  ∼  320 ka, due to either a higher sulfate flux or lower dilution of lake sulfate due to a smaller water volume. Diagenetic iron minerals appear more abundant during glacials, which are generally characterized by higher Fe / Ca ratios in the sediments. While in the lower part of the core the ferrimagnetic sulfide signal overprints the primary detrital magnetic signal, the upper part of the core is dominated by variable proportions of high- to low-coercivity iron oxides. Glacial sediments are characterized by high concentration of high-coercivity magnetic minerals (hematite, goethite), which relate to enhanced erosion of soils that had formed during preceding interglacials. Superimposed on the glacial–interglacial behavior are millennial-scale oscillations in the magnetic mineral composition that parallel variations in summer insolation. Like the processes on glacial–interglacial timescales, low summer insolation and a retreat in vegetation resulted in enhanced erosion of soil material. Our study highlights that rock-magnetic studies, in concert with geochemical and sedimentological investigations, provide a multi-level contribution to environmental reconstructions, since the magnetic properties can mirror both environmental conditions on land and intra-lake processes.

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Despite the strong increase in observational data on extrasolar planets, the processes that led to the formation of these planets are still not well understood. However, thanks to the high number of extrasolar planets that have been discovered, it is now possible to look at the planets as a population that puts statistical constraints on theoretical formation models. A method that uses these constraints is planetary population synthesis where synthetic planetary populations are generated and compared to the actual population. The key element of the population synthesis method is a global model of planet formation and evolution. These models directly predict observable planetary properties based on properties of the natal protoplanetary disc, linking two important classes of astrophysical objects. To do so, global models build on the simplified results of many specialized models that address one specific physical mechanism. We thoroughly review the physics of the sub-models included in global formation models. The sub-models can be classified as models describing the protoplanetary disc (of gas and solids), those that describe one (proto)planet (its solid core, gaseous envelope and atmosphere), and finally those that describe the interactions (orbital migration and N-body interaction). We compare the approaches taken in different global models, discuss the links between specialized and global models, and identify physical processes that require improved descriptions in future work. We then shortly address important results of planetary population synthesis like the planetary mass function or the mass-radius relationship. With these statistical results, the global effects of physical mechanisms occurring during planet formation and evolution become apparent, and specialized models describing them can be put to the observational test. Owing to their nature as meta models, global models depend on the results of specialized models, and therefore on the development of the field of planet formation theory as a whole. Because there are important uncertainties in this theory, it is likely that the global models will in future undergo significant modifications. Despite these limitations, global models can already now yield many testable predictions. With future global models addressing the geophysical characteristics of the synthetic planets, it should eventually become possible to make predictions about the habitability of planets based on their formation and evolution.

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At the mid-latitudes of Utopia Planitia (UP), Mars, a suite of spatially-associated landforms exhibit geomorphological traits that, on Earth, would be consistent with periglacial processes and the possible freeze-thaw cycling of water. The suite comprises small-sized polygonally-patterned ground, polygon-junction and -margin pits, and scalloped, rimless depressions. Typically, the landforms incise a dark-toned terrain that is thought to be ice-rich. Here, we investigate the dark-toned terrain by using high resolution images from the HiRISE as well as near-infrared spectral-data from the OMEGA and CRISM. The terrain displays erosional characteristics consistent with a sedimentary nature and near-infrared spectra characterised by a blue slope similar to that of weathered basaltic-tephra. We also describe volcanic terrain that is dark-toned and periglacially-modified in the Kamchatka mountain-range of eastern Russia. The terrain is characterised by weathered tephra inter-bedded with snow, ice-wedge polygons and near-surface excess ice. The excess ice forms in the pore space of the tephra as the result of snow-melt infiltration and, subsequently, in-situ freezing. Based on this possible analogue, we construct a three-stage mechanism that explains the possible ice-enrichment of a broad expanse of dark-toned terrain at the mid-latitudes of UP: (1) the dark-toned terrain accumulates and forms via the regional deposition of sediments sourced from explosive volcanism; (2) the volcanic sediments are blanketed by atmospherically-precipitated (H2O) snow, ice or an admixture of the two, either concurrent with the volcanic-events or between discrete events; and, (3) under the influence of high obliquity or explosive volcanism, boundary conditions tolerant of thaw evolve and this, in turn, permits the migration, cycling and eventual formation of excess ice in the volcanic sediments. Over time, and through episodic iterations of this scenario, excess ice forms to decametres of depth. (C) 2015 Elsevier B.V. All rights reserved.

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Adult monkeys (Macaca mulatta) with lesions of the hippocampal formation, perirhinal cortex, areas TH/TF, as well as controls were tested on tasks of object, spatial and contextual recognition memory. ^ Using a visual paired-comparison (VPC) task, all experimental groups showed a lack of object recognition relative to controls, although this impairment emerged at 10 sec with perirhinal lesions, 30 sec with areas TH/TF lesions and 60 sec with hippocampal lesions. In contrast, only perirhinal lesions impaired performance on delayed nonmatching-to-sample (DNMS), another task of object recognition memory. All groups were tested on DNMS with distraction (dDNMS) to examine whether the use of active cognitive strategies during the delay period could enable good performance on DNMS in spite of impaired recognition memory (revealed by the VPC task). Distractors affected performance of animals with perirhinal lesions at the 10-sec delay (the only delay in which their DNMS performance was above chance). They did not affect performance of animals with areas TH/TF lesions. Hippocampectomized animals were impaired at the 600-sec delay (the only delay at which prevention of active strategies would likely affect their behavior). ^ While lesions of areas TH/TF impaired spatial location memory and object-in-place memory, hippocampal lesions impaired only object-in-place memory. The pattern of results for perirhinal cortex lesions on the different task conditions indicated that this cortical area is not critical for spatial memory. ^ Finally, all three lesions impaired contextual recognition memory processes. The pattern of impairment appeared to result from the formation of only a global representation of the object and background, and suggests that all three areas are recruited for associating information across sources. ^ These results support the view that (1) the perirhinal cortex maintains storage of information about object and the context in which it is learned for a brief period of time, (2) areas TH/TF maintain information about spatial location and form associations between objects and their spatial relationship (a process that likely requires additional time) and (3) the hippocampal formation mediates associations between objects, their spatial relationship and the general context in which these associations are formed (an integrative function that requires additional time). ^

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Recent discoveries relating to the circulation of fluids within the oceanic crust include the finding of both important fluxes of elements and isotopes into the oceans by ridge-crest hydrothermal convection and important fluxes of heat out of the oceanic crust by convection at ridge crests and at some distance from ridge crests. In the present chapter, I present isotopic, chemical, and physical data from sediments and pore waters of Deep Sea Drilling Project (DSDP) Holes 503A and 503B. These results are modeled in terms of pore-water diffusion, advection, and production to ascertain the relative contribution of these processes at this location, 7.5 m.y. removed from ridge-crest hydrothermal activity. The observations made here contribute to the understanding of chemical and heat transport in oceanic crust of moderate age.

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El presente artículo tiene por objeto compartir algunas ideas sobre las prácticas profesionales de formación a partir de relatos de estudiantes y referencias teóricas que replantean algunos supuestos generalizados en el campo de la formación profesional. Con la intención de interrogar la imagen que muchas veces se plantea de las prácticas como ámbitos de integración y aplicación de saberes teóricos y procedimentales, los relatos e itinerarios teóricos propuestos en el texto, las muestran como tiempos de formación que suponen el abandono de una posición identitaria conocida -la de ser estudiante- para arriesgar allí otro rostro, otra palabra -la del profesional que quiere llegarse a ser-. En este tránsito se asoma algo del recién llegado, del extranjero, de aquel que emigra por primera vez de la propia casa para explorar otros mundos y dejarse sorprender en la difícil tarea de descubrirse a 'sí mismo' siendo 'otro'. En esta perspectiva, el artículo pretende aportar una mirada que abona la reflexión sobre los procesos de socialización y transmisión cultural que se desarrollan en las prácticas y sobre los efectos que esta experiencia genera en el plano identitario. Como corolario de este desarrollo plantea algunas consideraciones sobre la alternancia como estrategias de formación para el trabajo de claro potencial formativo y de alta complejidad en el plano organizativo y pedagógico

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El presente artículo tiene por objeto compartir algunas ideas sobre las prácticas profesionales de formación a partir de relatos de estudiantes y referencias teóricas que replantean algunos supuestos generalizados en el campo de la formación profesional. Con la intención de interrogar la imagen que muchas veces se plantea de las prácticas como ámbitos de integración y aplicación de saberes teóricos y procedimentales, los relatos e itinerarios teóricos propuestos en el texto, las muestran como tiempos de formación que suponen el abandono de una posición identitaria conocida -la de ser estudiante- para arriesgar allí otro rostro, otra palabra -la del profesional que quiere llegarse a ser-. En este tránsito se asoma algo del recién llegado, del extranjero, de aquel que emigra por primera vez de la propia casa para explorar otros mundos y dejarse sorprender en la difícil tarea de descubrirse a 'sí mismo' siendo 'otro'. En esta perspectiva, el artículo pretende aportar una mirada que abona la reflexión sobre los procesos de socialización y transmisión cultural que se desarrollan en las prácticas y sobre los efectos que esta experiencia genera en el plano identitario. Como corolario de este desarrollo plantea algunas consideraciones sobre la alternancia como estrategias de formación para el trabajo de claro potencial formativo y de alta complejidad en el plano organizativo y pedagógico

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Interstitial water and sediment samples of the Integrated Ocean Drilling Program (IODP) expedition 313 "New Jersey Shallow Shelf" were analyzed for chemical composition and stable isotope ratios. A total of 222 water samples were collected from the cores by Rhizon samplers and squeezing of fresh core material. Water was analyzed for its stable oxygen and hydrogen isotope geochemistry (d2H and d18O) at sites M0027A and M0029A, and the carbon isotope composition of the dissolved inorganic carbon (d13CDIC) (all sites). In addition, organic material (Corg) and inorganic carbonates from sediments were analyzed for their carbon ratios (d13Corg and d13Ccarb), and in case of the carbonates also for oxygen (d18Ocarb). Carbon isotopes were also analyzed in samples containing enough methane gas (d13Cmeth). Pore fluids from site M0027A were analyzed for the sulfur isotope composition of dissolved sulfate (d34S). The combination of isotope analyses of all phases (interstitial water, sediment, and gas) with pore water chemistry is expected to enable a better understanding of processes in the sediment and will help to identify the origin of fluids under the New Jersey shelf.

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El presente artículo tiene por objeto compartir algunas ideas sobre las prácticas profesionales de formación a partir de relatos de estudiantes y referencias teóricas que replantean algunos supuestos generalizados en el campo de la formación profesional. Con la intención de interrogar la imagen que muchas veces se plantea de las prácticas como ámbitos de integración y aplicación de saberes teóricos y procedimentales, los relatos e itinerarios teóricos propuestos en el texto, las muestran como tiempos de formación que suponen el abandono de una posición identitaria conocida -la de ser estudiante- para arriesgar allí otro rostro, otra palabra -la del profesional que quiere llegarse a ser-. En este tránsito se asoma algo del recién llegado, del extranjero, de aquel que emigra por primera vez de la propia casa para explorar otros mundos y dejarse sorprender en la difícil tarea de descubrirse a 'sí mismo' siendo 'otro'. En esta perspectiva, el artículo pretende aportar una mirada que abona la reflexión sobre los procesos de socialización y transmisión cultural que se desarrollan en las prácticas y sobre los efectos que esta experiencia genera en el plano identitario. Como corolario de este desarrollo plantea algunas consideraciones sobre la alternancia como estrategias de formación para el trabajo de claro potencial formativo y de alta complejidad en el plano organizativo y pedagógico

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Live-imaging techniques (LIT) utilize target-specific fluorescent dyes to visualize biochemical processes using confocal and multiphoton scanning microscopy, which are increasingly employed as non-invasive approach to physiological in-vivo and ex-vivo studies. Here we report application of LIT to bivalve gills for ex-vivo analysis of gill physiology and mapping of reactive oxygen (ROS) and nitrogen (RNS) species formation in the living tissue. Our results indicate that H2O2, HOO. and ONOO- radicals (assessed through C-H2DFFDA staining) are mainly formed within the blood sinus of the filaments and are likely to be produced by hemocytes as defense against invading pathogens. The oxidative damage in these areas is controlled by enhanced CAT (catalase) activities recorded within the filaments. The outermost areas of the ciliated epithelial cells composing the filaments, concentrated the highest mitochondrial densities (MTK Deep Red 633 staining) and the most acidic pH values (as observed with ageladine-a). These mitochondria have low (depolarized) membrane potentials (D psi m) (JC-1 staining), suggesting that the high amounts of ATP required for ciliary beating may be in part produced by non-mitochondrial mechanisms, such as the enzymatic activity of an ATP-regenerating kinase. Nitric oxide (NO, DAF-2DA staining) produced in the region of the peripheral mitochondria may have an effect on mitochondrial electron transport and possibly cause the low membrane potential. High DAF-2DA staining was moreover observed in the muscle cells composing the wall of the blood vessels where NO may be involved in regulating blood vessel diameter. On the ventral bend of the gills, subepithelial mucus glands (SMG) contain large mucous vacuoles showing higher fluorescence intensities for O2.- (DHE staining) than the rest of the tissue. Given the antimicrobial properties of superoxide, release of O2.- into the mucus may help to avoid the development of microbial biofilms on the gill surface. However, cells of the ventral bends are paying a price for this antimicrobial protection, since they show significantly higher oxidative damage, according to the antioxidant enzyme activities and the carbonyl levels, than the rest of the gill tissue. This study provides the first evidence that one single epithelial cell may contain mitochondria with significantly different membrane potentials. Furthermore, we provide new insight into ROS and RNS formation in ex-vivo gill tissues which opens new perspectives for unraveling the different ecophysiological roles of ROS and RNS in multifunctional organs such as gills.

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We examine the link between organic matter degradation, anaerobic methane oxidation (AMO), and sulfate depletion and explore how these processes potentially influence dolomitization. We determined rates and depths of AMO and dolomite formation for a variety of organic-rich sites along the west African Margin using data from Ocean Drilling Program (ODP) Leg 175. Rates of AMO are calculated from the diffusive fluxes of CH4 and SO4, and rates of dolomite formation are calculated from the diffusive flux of Mg. We find that the rates of dolomite formation are relatively constant regardless of the depth at which it is forming, indicating that the diffusive fluxes of Mg and Ca are not limiting. Based upon the calculated log IAP values, log K(sp) values for dolomite were found to narrowly range between -16.1 and -16.4. Dolomite formation is controlled in part by competition between AMO and methanogenesis, which controls the speciation of dissolved CO2. AMO increases the concentration of CO3[2-] through sulfate reduction, favoring dolomite formation, while methanogenesis increases the pCO2 of the pore waters, inhibiting dolomite formation. By regulating the pCO2 and alkalinity, methanogenesis and AMO can regulate the formation of dolomite in organic-rich marine sediments. In addition to providing a mechanistic link between AMO and dolomite formation, our findings provide a method by which the stability constant of dolomite can be calculated in modern sediments and allow prediction of regions and depth domains in which dolomite may be forming.