885 resultados para Transitive Inferences
Resumo:
IARG-AnCora tiene como objetivo la anotación con papeles temáticos de los argumentos implícitos de las nominalizaciones deverbales en el corpus AnCora. Estos corpus servirán de base para los sistemas de etiquetado automático de roles semánticos basados en técnicas de aprendizaje automático. Los analizadores semánticos son componentes básicos en las aplicaciones actuales de las tecnologías del lenguaje, en las que se quiere potenciar una comprensión más profunda del texto para realizar inferencias de más alto nivel y obtener así mejoras cualitativas en los resultados.
Resumo:
L’estudi de la neologia és indestriable de l’estudi del canvi lingüístic i, doncs, de la diacronia. Ens proposem ací descriure el procés de canvi semàntic que va experimentar el verb esmar, forma patrimonial del llatí *adaestimare, paral·lela del cultisme estimar. Aquesta recerca es fonamenta en l’aprofitament dels corpus textuals i altres materials despullats manualment. Sobre aquests materials, s’ha assajat l’anàlisi de la subjectivació i de les inferències que proposa la teoria de la inferència invitada del canvi semàntic (= TIICS).
Resumo:
The reprise evidential conditional (REC) is nowadays not very usual in Catalan: it is restricted to journalistic language and to some very formal genres (such as academic or legal language), it is not present in spontaneous discourse. On the one hand, it has been described among the rather new modality values of the conditional. On the other, the normative tradition tended to reject it for being a gallicism, or to describe it as an unsuitable neologism. Thanks to the extraction from text corpora, we surprisingly find this REC in Catalan from the beginning of the fourteenth century to the contemporary age, with semantic and pragmatic nuances and different evidence of grammaticalization. Due to the current interest in evidentiality, the REC has been widely studied in French, Italian and Portuguese, focusing mainly on its contemporary uses and not so intensively on the diachronic process that could explain the origin of this value. In line with this research, that we initiated studying the epistemic and evidential future in Catalan, our aim is to describe: a) the pragmatic context that could have been the initial point of the REC in the thirteenth century, before we find indisputable attestations of this use; b) the path of semantic change followed by the conditional from a ‘future in the past’ tense to the acquisition of epistemic and evidential values; and c) the role played by invited inferences, subjectification and intersubjectification in this change.
Resumo:
Factor markets that function well are a crucial condition for the competitiveness and growth of agriculture. Institutions and regulation may give rise to agricultural labour market heterogeneity, which could have important effects on the functioning of the labour market and other agricultural factor markets in EU member states. This paper first defines the institutional framework for the labour market, and then presents a brief literature review of previous studies of labour market institutional frameworks. Based on the literature, a survey to characterise agricultural labour markets was undertaken, which was implemented for a selection of EU27 and EU candidate countries, with responses based on expert opinion. The survey data were then used to construct indices of labour market flexibility/rigidity for the countries examined. These indices were used to make inter-country labour market comparisons and to draw inferences about the institutions and functioning of the agricultural labour market.
Resumo:
Records of mean sortable silt and planktonic foraminiferal preservation from the Ceará Rise (western equatorial Atlantic) and from the Caribbean are presented to analyze the Pliocene (3.5-2.2 Ma) to Pleistocene (1.6-0.3 Ma) evolution of near-bottom current strength and the carbonate corrosiveness of deep water. During the mid-Pleistocene climate transition (~1 Ma) a drastic decrease in glacial bottom current strength and an increase in carbonate corrosiveness is registered, demonstrating a substantial decrease in the glacial contribution of the Lower North Atlantic Deep Water (LNADW) to the Atlantic Ocean. Also, an increased sensitivity to eccentricity orbital forcing is registered after the MPT. By contrast, carbonate preservation increases considerably in the deep Caribbean in response to a strong and persistent stable contribution of Upper North Atlantic Deep Water (UNADW). We found evidence for the strongest and most stable circulation within the LNADW cell during the Northern Hemisphere cooling period between ~3.2 and 2.75 Ma. This is in agreement with the 'superconveyor model' which postulates that the highest NADW production took place prior to ~2.7 Ma. A considerable decrease in bottom current strength and planktonic foraminiferal preservation is observed synchronous with the first occurrence of large-scale continental ice sheets in the Northern Hemisphere. This documents the final termination of the 'superconveyor' at ca. 2.75 Ma. However, our data do not support a 'superconveyor' in the interval between 3.5 and 3.2 Ma when high-amplitude fluctuations in bottom current flow and preservation in planktonic foraminifera are observed. Because of the great sensitivity of NADW production to changes in surface water salinity, we assume that the high-amplitude fluctuations of LNADW circulation prior to ~3.2 Ma are linked to changes in the Atlantic salinity budget. After 2.75 Ma they are primarily controlled by ice-sheet forcing. In contrast to the stepwise deterioration of planktonic foraminiferal preservation in the western deep Atlantic, a trend toward better preservation from the Pliocene to Pleistocene is observed in the deep Caribbean. This indicates a long-term increase in the contribution of UNADW to the Atlantic Ocean.
Resumo:
We present a 5.3-Myr stack (the ''LR04'' stack) of benthic d18O records from 57 globally distributed sites aligned by an automated graphic correlation algorithm. This is the first benthic delta18O stack composed of more than three records to extend beyond 850 ka, and we use its improved signal quality to identify 24 new marine isotope stages in the early Pliocene. We also present a new LR04 age model for the Pliocene-Pleistocene derived from tuning the delta18O stack to a simple ice model based on 21 June insolation at 65 N. Stacked sedimentation rates provide additional age model constraints to prevent overtuning. Despite a conservative tuning strategy, the LR04 benthic stack exhibits significant coherency with insolation in the obliquity band throughout the entire 5.3 Myr and in the precession band for more than half of the record. The LR04 stack contains significantly more variance in benthic delta18O than previously published stacks of the late Pleistocene as the result of higher resolution records, a better alignment technique, and a greater percentage of records from the Atlantic. Finally, the relative phases of the stack's 41- and 23-kyr components suggest that the precession component of delta18O from 2.7-1.6 Ma is primarily a deep-water temperature signal and that the phase of d18O precession response changed suddenly at 1.6 Ma.
Resumo:
Benthic foraminiferal assemblages and the carbon isotope composition of the epifaunal benthic foraminifera Epistominella exigua and Fontbotia wuellerstorfi have been investigated along core MD02-2589 located at the southern Agulhas Plateau (41°26.03'S, 25°15.30'E, 2660 m water depth). This study aims to evaluate changes in the benthic paleoenvironment and its influence on benthic d13C with a notable focus on E. exigua, a species associated with phytodetritus deposits and poorly studied in isotope paleoceanographic reconstructions. The benthic foraminiferal assemblages (>63 µm) show large fluctuations in species composition suggesting significant changes in the pattern of ocean surface productivity conceivably related to migrations of the Subtropical Convergence (STC) and Subantarctic Front (SAF). Low to moderate seasonality and relatively higher food supply to the seafloor are indicated during glacial marine isotope stages (MIS) 6, 4, and 2 and during MIS 3, probably associated with the northward migration of the SAF and confluence with the more stationary STC above the southern flank of the Agulhas Plateau. The lowest organic carbon supply to the seafloor is indicated from late MIS 5b to MIS 4 as a consequence of increased influence of the Agulhas Front (AF) and/or weakening of the influence of the STC over the region. Episodic delivery of fresh organic matter, similar to modern conditions at the core location, is indicated during MIS 5c-MIS 5e and at Termination I. Comparison of this paleoenvironmental information with the paired d13C records of E. exigua and F. wuellerstorfi suggests that organic carbon offsets d13C of E. exigua from ambient bottom water d13CDIC, while its d13C amplitude, on glacial-interglacial timescales, does not seem affected by changes of organic carbon supply to the seafloor. This suggests that this species calcifies preferentially during the short time span of the year when productivity peaks and phytodetritus is delivered to the seafloor. Therefore E. exigua, while offset from d13CDIC, potentially more faithfully records the amplitude of ambient bottom water d13CDIC changes than F. wuellerstorfi, notably in settings such as the Southern Ocean that experienced substantial changes through time in the organic carbon supply to the seafloor.
Resumo:
The earliest Oligocene (~33.5 Ma) is marked by a major step in the long-term transition from an ice-free to glaciated world. The transition, characterized by both cooling and ice-sheet growth, triggered a transient but extreme glacial period designated Oi-1. High-resolution isotope records suggest that Oi-1 lasted for roughly 400,000 yr (the duration of magnetochron 13N) before partially abating, and that it was accompanied by an ocean-wide carbon isotope anomaly of 0.75?. One hypothesis relates the carbon isotope anomaly to enhanced export production brought about by climate-induced intensification of wind stress and upwelling, particularly in the Southern Ocean. To understand how this climatic event affected export production in the Southern Ocean, biogenic silica (opal) and carbonate accumulation rates were computed for the sub-polar Indian Ocean using deep-sea cores from ODP Site 744, Kerguelen Plateau. Our findings suggest that net productivity in this region increased by several fold in response to the Oi-1 glaciation. In addition, calcareous primary producers dominant in the Late Eocene were partially replaced by opaline organisms suggesting a trend toward seasonally greater surface divergence and upwelling in this sector of the Southern Ocean. We attribute these changes to intensification of atmospheric=oceanic circulation brought about by high-latitude cooling and the appearance of a full-scale continental ice-sheet on East Antarctica. Higher terrigenous sediment accumulation rates support the idea that wind-induced changes in regional productivity were augmented by an increased supply of glacial dust and debris that provided limiting micro-nutrients (e.g., iron-rich dust particles). We speculate that the rapid changes in biogenic sediment accumulation in the Southern Ocean and other upwelling-dominated regions contributed to the ocean-wide positive carbon isotope anomaly by temporarily increasing the burial rate of organic carbon relative to carbonate carbon. The changes in burial rates, in turn, may have produced a positive feedback on climate by briefly drawing down atmospheric pCO2 .
Resumo:
Oxygen isotope records, radiocarbon AMS data, carbonate and opal stratigraphy, sediment magnetic susceptibility, tephrachronology, and paleontological results were used to obtain detailed sediment stratigraphy and an age model for the studied cores. For studying sea-ice sedimentation an analysis of lithogenic grain number in >0.15 mm grain size fraction of bottom sediments was carried out. For quantitative estimation of intensity ice-rafting debris sedimentation number of IRD particles per sq cm per ka was calculated. Obtained results allowed to plot IRD AR distribution for the first oxygen isotope stage (0-12.5 14C ka, 14C) and for the second stage (12.5-24 14C ka). The first stage was subdivided into the latest deglaciation and the beginning of Holocene (6-12.5 14C ka) (transitive period), when the sea level was changing significantly, and the second part of Holocene (0-6 14C ka), when climate conditions and the sea level were similar to modern estimates. Data clearly show strong increase in ice formation in the glacial Sea of Okhotsk and its extent in the middle part of the sea. Average annual duration of ice coverage during glaciation was longer than that for interglaciation. However the sea ice cover was not continuous all the year round and disappeared in summer time except the far northwestern part of the sea.
Resumo:
A high-resolution (10-20 kyr) record of variations in CaCO3 content and dissolution was established for latest Cretaceous (last 0.7 Myr) deep-sea sediments from the South Atlantic Ocean (DSDP Site 516 from the Rio Grande Rise, and sites 525 and 527 from the Walvis Ridge). The degree of fragmentation of planktonic foraminifera (DFP) was used as a measure of calcite dissolution. High negative correlations between DFP and other independent measures of carbonate dissolution (percentage of sand fraction, absolute abundance of planktonic foraminifera, and planktonic/benthic foraminiferal ratio) validate its use as a sensitive index of calcite dissolution in upper Maastrichtian deep-sea sediments. Very high DFP and a significant negative correlation between DFP and CaCO 3 content suggest that Site 516 was located below the foraminiferal lysocline during the entire interval studied. Such a shallow position of the lysocline (paleodepth of Site 516 was 1.2 km) may be explained by "upwelling" of corrosive deep waters along the southern margin of the Rio Grande Rise. Sites 525 and 527 were located above the foraminiferal lysocline; however, three short periods of enhanced dissolution were recognised at Site 525 (paleodepth 1 km) and one interval of strong dissolution was identified at Site 527 (paleodepth 2.7 km). The lack of correspondence between the dissolution regimes at sites from the Walvis Ridge suggests limited deep-water communication across this physiographic barrier. Two of the dissolution maxima recognised at Site 525 correspond to carbonate maxima at Site 527. Variations in "upwelling" intensity along the Walvis Ridge, resulting in fluctuations in primary productivity in this area, may be the proximal cause of both carbonate cycles at Site 527 and dissolution cycles at Site 525. We suggest that development of the bottom Ekman layer between a hypothetical westward geostrophic current and the topographical height of the Rio Grande Rise-Walvis Ridge system may be a plausible hydrodynamical explanation for the proposed "'upwelling" along the southern margin of this topographical structure.