Interpretações semânticas no pretérito perfeito: pretérito ou presente

An analysis of “Pretérito Perfeito Simples” (Simple Past Tense) and “Pretérito Per‐ feito Composto” (Compound Past Tense) in Brazilian Portuguese showed that such tenses must be distinguished according to semantic and pragmatic features other than temporal; both tenses can be used to express a situation that begins in the past and extends up to the present.

Development And Use Of A Model To Predict Properties Of Infiltrated Solid Oxide Fuel Cell Anodes

Solid oxide fuel cells (SOFCs) provide a potentially clean way of using energy sources. One important aspect of a functioning fuel cell is the anode and its characteristics (e.g. conductivity). Using infiltration of conductor particles has been shown to be a method for production at lower cost with comparable functionality. While these methods have been demonstrated experimentally, there is a vast range of variables to consider. Because of the long time for manufacture, a model is desired to aid in the development of the desired anode formulation. This thesis aims to (1) use an idealized system to determine the appropriate size and aspect ratio to determine the percolation threshold and effective conductivity as well as to (2) simulate the infiltrated fabrication method to determine the effective conductivity and percolation threshold as a function of ceramic and pore former particle size, particle fraction and the cell¿s final porosity. The idealized system found that the aspect ratio of the cell does not affect the cells functionality and that an aspect ratio of 1 is the most efficient computationally to use. Additionally, at cell sizes greater than 50x50, the conductivity asymptotes to a constant value. Through the infiltrated model simulations, it was found that by increasing the size of the ceramic (YSZ) and pore former particles, the percolation threshold can be decreased and the effective conductivity at low loadings can be increased. Furthermore, by decreasing the porosity of the cell, the percolation threshold and effective conductivity at low loadings can also be increased

Multi-phase postmortem CT angiography: recognizing technique-related artefacts and pitfalls

BACKGROUND AND PURPOSE Multi-phase postmortem CT angiography (MPMCTA) is increasingly being recognized as a valuable adjunct medicolegal tool to explore the vascular system. Adequate interpretation, however, requires knowledge about the most common technique-related artefacts. The purpose of this study was to identify and index the possible artefacts related to MPMCTA. MATERIAL AND METHODS An experienced radiologist blinded to all clinical and forensic data retrospectively reviewed 49 MPMCTAs. Each angiographic phase, i.e. arterial, venous and dynamic, was analysed separately to identify phase-specific artefacts based on location and aspect. RESULTS Incomplete contrast filling of the cerebral venous system was the most commonly encountered artefact, followed by contrast agent layering in the lumen of the thoracic aorta. Enhancement or so-called oedematization of the digestive system mucosa was also frequently observed. CONCLUSION All MPMCTA artefacts observed and described here are reproducible and easily identifiable. Knowledge about these artefacts is important to avoid misinterpreting them as pathological findings.

Comparisons of observed ice properties and Envisat Advanced Synthetic Aperture Radar (ASAR) data during Nathanial B. Palmer cruise NBP09-01 and Oden cruise OSO08/09

Envisat Advanced Synthetic Aperture Radar (ASAR) Wide Swath Mode (WSM) images are used to derive C-band HH-polarization normalized radar cross sections (NRCS). These are compared with ice-core analysis and visual ship-based observations of snow and ice properties observed according to the Antarctic Sea Ice Processes and Climate (ASPeCt) protocol during two International Polar Year summer cruises (Oden 2008 and Palmer 2009) in West Antarctica. Thick first-year (TFY) and multi-year (MY) ice were the dominant ice types. The NRCS value ranges between -16.3 ± 1.1 and -7.6 ± 1.0 dB for TFY ice, and is -12.6 ± 1.3 dB for MY ice; for TFY ice, NRCS values increase from ~-15 dB to -9 dB from December/January to mid-February. In situ and ASPeCt observations are not, however, detailed enough to interpret the observed NRCS change over time. Co-located Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E) vertically polarized 37 GHz brightness temperatures (TB37V), 7 day and 1 day averages as well as the TB37V difference between ascending and descending AMSR-E overpasses suggest the low NRCS values (-15 dB) are associated with snowmelt being still in progress, while the change towards higher NRCS values (-9dB) is caused by commencement of melt-refreeze cycles after about mid-January.

Flow conditions, bed form dimensions and shear stress experiments

Large asymmetric bed forms commonly develop in rivers. The turbulence associated with flow separation that develops over their steep lee side is responsible for the form shear stress which can represent a substantial part of total shear stress in rivers. This paper uses the Delft3D modeling system to investigate the effects of bed form geometry and forcing conditions on flow separation length and associated turbulence, and bed form shear stress over angle-of-repose (30 lee side angle) bed forms. The model was validated with lab measurements that showed sufficient agreement to be used for a systematic analysis. The influence of flow velocity, bed roughness, relative height (bed form height/water depth), and aspect ratio (bed form height/length) on the variations of the normalized length of the flow separation zone, the extent of the wake region (where the turbulent kinetic energy (TKE) was more than 70% of the maximum TKE), the average TKE within the wake region and the form shear stress were investigated. Form shear stress was found not to scale with the size of the flow separation zone but to be related to the product of the normalized extent of the wake region (extent of the wake region/extent of water body above the bed form) and the average TKE within the wake region. The results add to understanding of the hydrodynamics of bed forms and may be used for the development of better parameterizations of smallscale processes for application in large-scale studies.

Preparation and characterization of polyester resin-layered silicate containing reactive groups

Polymer nanocomposites, specifically nanoclay-reinforced polymers, have attracted great interest as matrix materials for high temperature composite applications. Nanocomposites require relatively low dispersant loads to achieve significant property enhancements. These enhancements are mainly a consequence of the interfacial effects that result from dispersing the silicate nanolayers in the polymer matrix and the high in-plane strength, stiffness and aspect ratio of the lamellar nanoparticles. The montmorillonite (MMT) clay, modified with organic onium ions with long alkyl chains as Cloisites, has been widely used to obtain nanocomposites. The presence of reactive groups in organic onium ions can form chemical bonds with the polymer matrix which favours a very high exfoliation degree of the clay platelets in the nanocomposite (1,2)

Mortality and climatic/environmental correlates of Widdringtonia cedargensis trees in the Cederberg, South Africa

Background: Conifer populations appear disproportionately threatened by global change. Most examples are, however, drawn from the northern hemisphere and long-term rates of population decline are not well documented as historical data are often lacking. We use a large and long-term (1931-2013) repeat photography dataset together with environmental data and fire records to account for the decline of the critically endangered Widdringtonia cedarbergensis. Eighty-seven historical and repeat photo-pairs were analysed to establish 20th century changes in W. cedarbergensis demography. A generalized linear mixed-effects model was fitted to determine the relative importance of environmental factors and fire-return interval on mortality for the species. Results: From an initial total of 1313 live trees in historical photographs, 74% had died and only 44 (3.4%) had recruited in the repeat photographs, leaving 387 live individuals. Juveniles (mature adults) had decreased (increased) from 27% (73%) to 8% (92%) over the intervening period. Our model demonstrates that mortality is related to greater fire frequency, higher temperatures, lower elevations, less rocky habitats and aspect (i.e. east-facing slopes had the least mortality). Conclusions: Our results show that W. cedarbergensis populations have declined significantly over the recorded period, with a pronounced decline in the last 30 years. Individuals that established in open habitats at lower, hotter elevations and experienced a greater fire frequency appear to be more vulnerable to mortality than individuals growing within protected, rocky environments at higher, cooler locations with less frequent fires. Climate models predict increasing temperatures for our study area (and likely increases in wildfires). If these predictions are realised, further declines in the species can be expected. Urgent management interventions, including seedling out-planting in fire-protected high elevation sites, reducing fire frequency in higher elevation populations, and assisted migration, should be considered.

Imperative, subjunctive, and the desiderative-appellative space in Spanish

After defining the “enunciative scheme” (sentence type) as a communicative unit, the imperative is characterized as a morphologized modality of appellative kind used when the following conditions occur: appellative meaning, 2nd person, future tense and absence of negation. In Spanish, any variation of any of these requirements determines that the subjunctive is used. We reject the idea that the imperative is a variant of subjunctive specialized in appellative function and that both modes share a desiderative morpheme. Working in this way means attributing to a morphological category of the verb a property that actually corresponds to the enunciative schemes (sentence types). We propose to integrate the imperative and subjunctive in the framework of what we call the “desiderative-appellative space”. This “space” brings together various grammatical or grammaticalized means based on the imperative and the subjunctive. Semantically, it is organized around a component of desirability (action appears as desirable) that, by varying several factors, configures a route that goes from a center (the imperative) to a periphery (the expression of desire).

Episodic Future Thinking in 4-Year-Olds, Poster Symposium: The who, what, where and when of episodic foresight development

The ability to project oneself into the future to pre-experience an event is referred to as episodic future thinking (Atance & O’Neill, 2001). Only a relatively small number of studies have attempted to measure this ability in pre-school aged children (Atance & Meltzoff, 2005; Busby & Suddendorf, 2005ab, 2010; Russell, Alexis, & Clayton, 2010).Perhaps the most successful method is that used by Russell et al (2010). In this task, 3- to 5-year-olds played a game of blow football on one end of a table. After this children were asked to select tools that would enable them to play the same game tomorrow from the opposite, unreachable, side of the table. Results indicated that only 5-year-olds were capable of selecting the right objects for future use more often than would be expected by chance. Above-chance performance was observed in this older group even though most children failed the task because there was a low probability of selecting the correct 2 objects from a choice of 6 by chance.This study aimed to identify the age at which children begin to consistently pass this type of task. Three different tasks were designed in which children played a game on one side of a table, and then were asked to choose a tool to play a similar game on the other side of the table the next day. For example, children used a toy fishing rod to catch magnetic fish on one side of the table; playing the same game from the other side of the table required a different type of fishing rod. At test, children chose between just 2 objects: the tool they had already used, which would not work on the other side, and a different tool that they had not used before but which was suitable for the other side of the table. Experiment 1: Forty-eight 4-year-olds (M = 53.6 months, SD = 2.9) took part. These children were assigned to one of two conditions: a control condition (present-self) where the key test questions were asked in the present tense and an experimental condition (future-self) where the questions were in the future tense. Surprisingly, the results showed that both groups of 4-year-olds selected the correct tool at above chance levels (Table 1 shows the mean number of correct answers out of three). However, the children could see the apparatus when they answered the test questions and so perhaps answered them correctly without imagining the future. Experiment 2: Twenty-four 4-year-olds (M = 53.7, SD = 3.1) participated. Pre-schoolers in this study experienced one condition: future-self looking-away. In this condition children were asked to turn their backs to the games when answering the test questions, which were in the future tense. Children again performed above chance levels on all three games.Contrary to the findings of Russell et al. (2010), our results suggest that episodic future thinking skills could be present in 4-year-olds, assuming that this is what is measured by the tasks. Table 1. Mean number of correct answers across the three games in Experiments 1 and 2Experimental Conditions (N=24 in each condition)Mean CorrectStandardDeviationStatistical SignificanceExp. 1 (present-self, look) – 2 items2.750.68p < 0.001Exp. 1 (future-self, look) – 2 items 2.790.42p < 0.001Exp. 2 (future-self, away) – 2 items 2.330.64p < 0.001Exp. 3 (future-self away) – 3 items1.210.98p = 0.157

Assessing the influence of abiotic factors and leaf-level properties on the stability of growing-season canopy greenness in a deciduous forest

Maps depicting spatial pattern in the stability of summer greenness could advance understanding of how forest ecosystems will respond to global changes such as a longer growing season. Declining summer greenness, or “greendown”, is spectrally related to declining near-infrared reflectance and is observed in most remote sensing time series to begin shortly after peak greenness at the end of spring and extend until the beginning of leaf coloration in autumn,. Understanding spatial patterns in the strength of greendown has recently become possible with the advancement of Landsat phenology products, which show that greendown patterns vary at scales appropriate for linking these patterns to proposed environmental forcing factors. This study tested two non-mutually exclusive hypotheses for how leaf measurements and environmental factors correlate with greendown and decreasing NIR reflectance across sites. At the landscape scale, we used linear regression to test the effects of maximum greenness, elevation, slope, aspect, solar irradiance and canopy rugosity on greendown. Secondly, we used leaf chemical traits and reflectance observations to test the effect of nitrogen availability and intrinsic water use efficiency on leaf-level greendown, and landscape-level greendown measured from Landsat. The study was conducted using Quercus alba canopies across 21 sites of an eastern deciduous forest in North America between June and August 2014. Our linear model explained greendown variance with an R2=0.47 with maximum greenness as the greatest model effect. Subsequent models excluding one model effect revealed elevation and aspect were the two topographic factors that explained the greatest amount of greendown variance. Regression results also demonstrated important interactions between all three variables, with the greatest interaction showing that aspect had greater influence on greendown at sites with steeper slopes. Leaf-level reflectance was correlated with foliar δ13C (proxy for intrinsic water use efficiency), but foliar δ13C did not translate into correlations with landscape-level variation in greendown from Landsat. Therefore, we conclude that Landsat greendown is primarily indicative of landscape position, with a small effect of canopy structure, and no measureable effect of leaf reflectance. With this understanding of Landsat greendown we can better explain the effects of landscape factors on vegetation reflectance and perhaps on phenology, which would be very useful for studying phenology in the context of global climate change

Simulating the effects of vegetation and landscape structure on fire behavior in northeastern Portugal: the case of holm oak (Quercus rotundifolia)

O fogo é um processo frequente nas paisagens do norte de Portugal. Estudos anteriores mostraram que os bosques de azinheira (Quercus rotundifolia) persistem após a passagem do fogo e ajudam a diminuir a sua intensidade e taxa de propagação. Os principais objetivos deste estudo foram compreender e modelar o efeito dos bosques de azinheira no comportamento do fogo ao nível da paisagem da bacia superior do rio Sabor, localizado no nordeste de Portugal. O impacto dos bosques de azinheira no comportamento do fogo foi testado em termos de área e configuração de acordo com cenários que simulam a possível distribuição destas unidades de vegetação na paisagem, considerando uma percentagem de ocupação da azinheira de 2.2% (Low), 18.1% (Moderate), 26.0% (High), e 39.8% (Rivers). Estes cenários tiveram como principal objetivo testar 1) o papel dos bosques de azinheira no comportamento do fogo e 2) de que forma a configuração das manchas de azinheira podem ajudar a diminuir a intensidade da linha de fogo e área ardida. Na modelação do comportamento do fogo foi usado o modelo FlamMap para simular a intensidade de linha do fogo e taxa de propagação do fogo com base em modelos de combustível associados a cada ocupação e uso do solo presente na área de estudo, e também com base em fatores topográficos (altitude, declive e orientação da encosta) e climáticos (humidade e velocidade do vento). Foram ainda usados dois modelos de combustível para a ocupação de azinheira (áreas interiores e de bordadura), desenvolvidos com base em dados reais obtidos na região. Usou-se o software FRAGSATS para a análise dos padrões espaciais das classes de intensidade de linha do fogo, usando-se as métricas Class Area (CA), Number of Patches (NP) e Large Patches Index (LPI). Os resultados obtidos indicaram que a intensidade da linha de fogo e a taxa de propagação do fogo variou entre cenários e entre modelos de combustível para o azinhal. A intensidade média da linha de fogo e a taxa média de propagação do fogo decresceu à medida que a percentagem de área de bosques de azinheira aumentou na paisagem. Também foi observado que as métricas CA, NP e LPI variaram entre cenários e modelos de combustível para o azinhal, decrescendo quando a percentagem de área de bosques de azinheira aumentou. Este estudo permitiu concluir que a variação da percentagem de ocupação e configuração espacial dos bosques de azinheira influenciam o comportamento do fogo, reduzindo, em termos médios, a intensidade da linha de fogo e a taxa de propagação, sugerindo que os bosques de azinhal podem ser usados como medidas silvícolas preventivas para diminuir o risco de incêndio nesta região.

Regional variation and change in the history of English strong verbs

This thesis investigates how the strong verb system inherited from Old English evolved in the regional dialects of Middle English (ca. 1100-1500). Old English texts preserve a relatively complex system of strong verbs, in which traditionally seven different ablaut classes are distinguished. This system becomes seriously disrupted from the Late Old English and Early Middle English periods onwards. As a result, many strong verbs die out, or have their ablaut patterns affected by sound change and morphological analogy, or transfer to the weak conjugation. In my thesis, I study the beginnings of two of these developments in two strong verb classes to find out what the evidence from Middle English regional dialects can tell us about their origins and diffusion. Chapter 2 concentrates on the strong-to-weak shift in Class III verbs, and investigates to what extent strong, mixed and weak past tense and participle forms vary in Middle English dialects, and whether the variation is more pronounced in the paradigms of specific verbs or sub-classes. Chapter 3 analyses the regional distribution of ablaut levelling in strong Class IV verbs throughout the Middle English period. The Class III and IV data for the Early Middle English period are drawn from A Linguistic Atlas of Early Middle English, and the data for the Late Middle English period from a sub-corpus of files from The Penn-Helsinki Parsed Corpus of Middle English and The Middle English Grammar Corpus. Furthermore, The English Dialect Dictionary and Grammar are consulted as an additional reference point to find out to what extent the Middle English developments are reflected in Late Modern English dialects. Finally, referring to modern insights into language variation and change and linguistic interference, Chapter 4 discusses to what extent intra- and extra-linguistc factors, such as token and type frequency, stem structure and language contact, might correlate with the strong-to-weak shift and ablaut levelling in Class III and IV verbs in the Middle English period. The thesis is accompanied by six appendices that contain further information about my distinction of Middle English dialect areas (Appendix A), historical Class III and IV verbs (B and C) and the text samples and linguistic data from the Middle English text corpora (D, E and F).

The alternation of pronoun forms te and lhe in personal letters of Ceará

This study aims to analyze the alternation of pronouns “te” and “lhe” for the 2nd PESS SING, in personal letters written in Portuguese in the State of Ceará, Brazil, during the twentieth century, in the light of the theoretical and methodological assumptions of Variationist Sociolinguistics (LABOV, 1972, 1994). The sample to be analyzed is composed of 186 personal letters. It seeks to investigate the actions of groups of linguistic factors tense and pronoun position in relation to the verb in the alternation of social forms. Then are presented the results of this alternation by senders of the letters, in order to refine the analysis and describe the distribution of these forms by author. Data were submitted to the computer program GoldVarb X (SANKOFF; TAGLIAMONTE; SMITH, 2005) and indicate that the alternation “te”/“lhe” presents percentages rather balanced when considering the analysis of all the letters. In the analysis by sender, the results demonstrate that there are authors who only used “te”, and authors only used “lhe”, and authors that make the alternation “te” / “lhe” in their writing. 

Comparison of three expert elicitation methods for logistic regression on predicting the presence of the threatened brush-tailed rock-wallaby petrogale penicillata

Numerous expert elicitation methods have been suggested for generalised linear models (GLMs). This paper compares three relatively new approaches to eliciting expert knowledge in a form suitable for Bayesian logistic regression. These methods were trialled on two experts in order to model the habitat suitability of the threatened Australian brush-tailed rock-wallaby (Petrogale penicillata). The first elicitation approach is a geographically assisted indirect predictive method with a geographic information system (GIS) interface. The second approach is a predictive indirect method which uses an interactive graphical tool. The third method uses a questionnaire to elicit expert knowledge directly about the impact of a habitat variable on the response. Two variables (slope and aspect) are used to examine prior and posterior distributions of the three methods. The results indicate that there are some similarities and dissimilarities between the expert informed priors of the two experts formulated from the different approaches. The choice of elicitation method depends on the statistical knowledge of the expert, their mapping skills, time constraints, accessibility to experts and funding available. This trial reveals that expert knowledge can be important when modelling rare event data, such as threatened species, because experts can provide additional information that may not be represented in the dataset. However care must be taken with the way in which this information is elicited and formulated.

Prandtl number scaling of natural convection of an inclined flat plate due to uniform surface heat flux

A new scaling analysis has been performed for the unsteady natural convection boundary layer under a downward facing inclined plate with uniform heat flux. The development of the thermal or viscous boundary layers may be classified into three distinct stages including a start-up stage, a transitional stage and a steady stage, which can be clearly identified in the analytical as well as numerical results. Earlier scaling shows that the existing scaling laws of the boundary layer thickness, velocity and steady state time scale for the natural convection flow on a heated plate of uniform heat flux provide a very poor prediction of the Prandtl number dependency of the flow. However, those scalings performed very well with Rayleigh number and aspect ratio dependency. In this study, a new Prandtl number scaling has been developed using a triple-layer integral approach for Pr > 1. It is seen that in comparison to the direct numerical simulations, the new scaling performs considerably better than the previous scaling.