1520 BH17 NP 2014

Dark brown sediment with clasts ranging from small to large in size. Clast shape ranges from angular to sub-rounded. Lineations can be seen throughout the sample, along with a few rotation and comet structures. This sample also contains a fine grained clay domain that is relatively structure-less. It can be seen scattered throughout the sample.

1539 BH17 NP 2014

Brown sediment with clasts ranging from small to large. Clast shape ranges from angular to sub-rounded. Lineations are common throughout the sample. This sample also contains a clay domain, that appears very fine grained. Edge-to-edge grain crushing, comet structures, and rotation structures are also present.

Étude de la négativité de discordance dans l'amusie congénitale

L’amusie congénitale est un trouble neuro-développemental qui s’exprime par un déficit de discrimination tonale fine. Le cerveau des amusiques ne répond pas aux petites différences de hauteur, tel que révélé par l’absence de la composante de potentiel évoqué P3b, qui est associée aux processus de discrimination tonale tardifs et conscients. Peu d’études se sont penchées sur les mécanismes précoces et préconscients de discrimination tonale chez les amusiques, qui peuvent être étudiés par l’entremise d’une composante de potentiel évoqué appelée la négativité de discordance (MMN). Certaines études ont démontré qu’il est possible d’enregistrer la MMN pendant la présentation d’un film avec la trame sonore en simultané aux sons visant à évoquer la composante. Toutefois, une étude a démontré que la présentation de la trame sonore réduisait l’amplitude de la MMN, sans néanmoins clarifier la nature de l’effet d’interférence en cause. Les objectifs du présent projet sont d’abord, d’investiguer les effets à l’origine de la réduction d’amplitude de la MMN observée lors de la présentation d’un film avec la trame sonore, puis d’évaluer cette même composante chez les amusiques. La première étude visait à déterminer si un effet d’interférence attentionnelle ou acoustique était en cause dans la réduction d’amplitude observée sur la MMN lors de la présentation de la trame sonore d’un film. Les résultats ont montré qu’un effet de masquage acoustique, attribuable à la trame sonore, était responsable de la réduction d’amplitude de la MMN, cette dernière augmentant au fur et à mesure que l’intensité sonore de la trame du film était réduite. La seconde étude a été conduite dans le but d’investiguer la MMN chez les amusiques et de vérifier si le complexe d’ondes anormales N2b-P3b, observé en réponse aux grandes différences tonales chez les amusiques, pouvait être attribuable à un effet de saillance des stimuli. Dans un premier temps, nous avons comparé la MMN des amusiques à celle des contrôles, puis nous avons modifié le paradigme expérimental visant à évoquer la N2b-P3b en ajustant les probabilités d’occurrence des sons présentés aux contrôles en fonction des sons perçus par les amusiques. Les résultats ont montré que le cerveau des amusiques parvient à discriminer les différences de hauteur à un niveau précoce et préconscient, tel que révélé par une MMN normale, mais que les réponses cérébrales plus tardives, associées au processus de discrimination des hauteurs conscient, sont anormales chez les amusiques, et ce, uniquement pour les petites différences de hauteur, tel que révélé par l’absence de la P3b. En conclusion, ces résultats démontrent que l’amplitude de la MMN est affectée de manière significative par la présentation de la trame sonore d’un film et que cela est attribuable à un effet d’interférence acoustique. Dans un deuxième temps, nous avons démontré que les mécanismes précoces et préconscients de discrimination tonale sont préservés chez les amusiques, et que le déficit sous-jacent à l’amusie congénitale est attribuable à une atteinte du processus de discrimination tonale fine associé à un niveau de traitement cérébral tardif et conscient, le complexe d’ondes anormales N2b-P3b étant pour sa part attribuable à un effet de saillance des stimuli.

Les discours ruraux, urbains et périurbains du cinéma québécois

Ce projet s’intéresse aux représentations que fait le cinéma des territoires et à la manière dont ces représentations reflètent des grands enjeux socio-spatiaux. L’espace cinématographique devient une clé d’entrée pour l’analyse géographique. Cette analyse porte plus particulièrement sur les représentations que fait le cinéma québécois contemporain des espaces urbains, ruraux et périurbains. Les récits et les représentations spatiales qui les composent se positionnent souvent sur les enjeux socio-spatiaux, produits par l’histoire nationale et les processus socioéconomiques. La proposition d’analyser les représentations cinématographiques en lien avec le contexte socioéconomique vise deux principaux objectifs conceptuels. D’une part, elle s’intéresse à une meilleure compréhension du façonnement des discours sur l’espace, en ce qui a trait à leur émergence et leur négociation. D’autre part, l’analyse vise une définition élargie des espaces ruraux, urbains et périurbains contemporains, en révélant la complexité et simultanément, la simplification dont ils font l’objet, ainsi que les enjeux qui leurs sont associés. Il s’agit d’exploiter la cinématographie québécoise comme un outil d’analyse qui permet de dévoiler la diversité des discours socio-spatiaux. Des approches quantitatives et qualitatives d’interprétation des discours sont jumelées pour réaliser une analyse complète. La méthode retenue est l’analyse critique du discours (ACD), qui tient compte des rapports idéologiques et vise à la dénaturalisation du discours. En quelques mots, l’analyse consiste en l’identification de relations entre les représentations spatiales et le contexte socioéconomique duquel elles ont émergé. Le cadre opérationnel est constitué d’un corpus de 50 films québécois réalisés entre 1980-2008, « lus » à l’aide d’une grille de lecture originale et analysés avec des méthodes d’analyse spatiale et statistique, combinées à une interprétation qualitative. L’analyse quantitative révèle que le monde urbain et le monde rural sont souvent mis en opposition. Les films font de Montréal le principal pôle urbain, tandis que le reste du Québec est associé au milieu rural. Influencées par les flux culturels et économiques globaux, les représentations montréalaises suggèrent une ville fragmentée et continuellement en mouvement. En opposition à ces représentations urbaines, les cinéastes envisagent l’espace rural comme étant exempt de travail, axé sur le chez-soi et doté d’un esprit communautaire. Il est suggéré que la ville, toujours en croissance, restreint les possibilités d’un développement communautaire fort. Face à une ville transformée par la globalisation et en perte d’authenticité, une forme de régionalisme est observée. Ce dernier associe un ensemble de valeurs à une communauté ou à un territoire, afin de se distinguer devant des forces globalisantes qui semblent homogénéiser les valeurs. Pourtant, l’analyse quantitative laisse voir des contradictions au sein de chaque entité géographique ou milieu. L’analyse qualitative permet d’approfondir l’interprétation et révèle sept grands discours sur les espaces urbains et ruraux. Sont notamment identifiés des discours sur la contestation de la modernité urbaine, sur la réappropriation du milieu de vie par les citoyens et sur un espace rural parfois brutal. Cette analyse amène à conclure que la diversité des discours s’explique par l’hétérogénéité des pratiques socio-spatiales, qui remettent en question l’idée d’un discours national homogène. Cela témoigne de l’évolution et la négociation des regards que nous posons sur nos espaces. Au final, cette thèse contribue à une meilleure utilisation du matériel cinématographique comme support d’étude géographique en proposant une approche méthodologique claire et originale. Sur un plan conceptuel, elle rappelle la complexité et le dynamisme des représentations territoriales québécoises, ainsi que les stratégies de négociation des cinéastes face aux enjeux socio-spatiaux vécus dans la province.

Intervariability of Phosphorus Speciation in Selected Mangrove Ecosystems Around the Greater Cochin

Mangrove forests are best developed on tropical shorelines where there is an extensive intertidal zone, with an abundant supply of fine-grained sediment. It receives a mixture of liable and refractory organic and inorganic phosphorus compounds from the overlying water and the surrounding landmasses. Organic phosphorus is not available for mangrove plant nutrition. While inorganic phosphate represents the largest potential pool of plant-available and which are bound in the form of Ca, Fe and Al phosphate. It deals with the scientific investigations on mangrove systems in the Kerala coastline and to investigate nutrient distribution of mangrove ecosystems of greater Cochin area. It discusses the description of study areas such as Murikkumpadam-Vypeen Island and Aroor. Then it deals with the spatial and seasonal distribution of dissolved ammonia, nitrite, nitrate, inorganic phosphate, organic phosphate and the total phosphorus in surface waters of mangrove fringed creeks. Then it discusses the geochemical compositions of mangrove-fringed sediments and also the chemical speciation of phosphorus in sediment cores.

Dataflow Computation for the J-Machine

The dataflow model of computation exposes and exploits parallelism in programs without requiring programmer annotation; however, instruction- level dataflow is too fine-grained to be efficient on general-purpose processors. A popular solution is to develop a "hybrid'' model of computation where regions of dataflow graphs are combined into sequential blocks of code. I have implemented such a system to allow the J-Machine to run Id programs, leaving exposed a high amount of parallelism --- such as among loop iterations. I describe this system and provide an analysis of its strengths and weaknesses and those of the J-Machine, along with ideas for improvement.

Reconfigurable Architectures for General-Purpose Computing

General-purpose computing devices allow us to (1) customize computation after fabrication and (2) conserve area by reusing expensive active circuitry for different functions in time. We define RP-space, a restricted domain of the general-purpose architectural space focussed on reconfigurable computing architectures. Two dominant features differentiate reconfigurable from special-purpose architectures and account for most of the area overhead associated with RP devices: (1) instructions which tell the device how to behave, and (2) flexible interconnect which supports task dependent dataflow between operations. We can characterize RP-space by the allocation and structure of these resources and compare the efficiencies of architectural points across broad application characteristics. Conventional FPGAs fall at one extreme end of this space and their efficiency ranges over two orders of magnitude across the space of application characteristics. Understanding RP-space and its consequences allows us to pick the best architecture for a task and to search for more robust design points in the space. Our DPGA, a fine- grained computing device which adds small, on-chip instruction memories to FPGAs is one such design point. For typical logic applications and finite- state machines, a DPGA can implement tasks in one-third the area of a traditional FPGA. TSFPGA, a variant of the DPGA which focuses on heavily time-switched interconnect, achieves circuit densities close to the DPGA, while reducing typical physical mapping times from hours to seconds. Rigid, fabrication-time organization of instruction resources significantly narrows the range of efficiency for conventional architectures. To avoid this performance brittleness, we developed MATRIX, the first architecture to defer the binding of instruction resources until run-time, allowing the application to organize resources according to its needs. Our focus MATRIX design point is based on an array of 8-bit ALU and register-file building blocks interconnected via a byte-wide network. With today's silicon, a single chip MATRIX array can deliver over 10 Gop/s (8-bit ops). On sample image processing tasks, we show that MATRIX yields 10-20x the computational density of conventional processors. Understanding the cost structure of RP-space helps us identify these intermediate architectural points and may provide useful insight more broadly in guiding our continual search for robust and efficient general-purpose computing structures.

ADAM: A Decentralized Parallel Computer Architecture Featuring Fast Thread and Data Migration and a Uniform Hardware Abstraction

The furious pace of Moore's Law is driving computer architecture into a realm where the the speed of light is the dominant factor in system latencies. The number of clock cycles to span a chip are increasing, while the number of bits that can be accessed within a clock cycle is decreasing. Hence, it is becoming more difficult to hide latency. One alternative solution is to reduce latency by migrating threads and data, but the overhead of existing implementations has previously made migration an unserviceable solution so far. I present an architecture, implementation, and mechanisms that reduces the overhead of migration to the point where migration is a viable supplement to other latency hiding mechanisms, such as multithreading. The architecture is abstract, and presents programmers with a simple, uniform fine-grained multithreaded parallel programming model with implicit memory management. In other words, the spatial nature and implementation details (such as the number of processors) of a parallel machine are entirely hidden from the programmer. Compiler writers are encouraged to devise programming languages for the machine that guide a programmer to express their ideas in terms of objects, since objects exhibit an inherent physical locality of data and code. The machine implementation can then leverage this locality to automatically distribute data and threads across the physical machine by using a set of high performance migration mechanisms. An implementation of this architecture could migrate a null thread in 66 cycles -- over a factor of 1000 improvement over previous work. Performance also scales well; the time required to move a typical thread is only 4 to 5 times that of a null thread. Data migration performance is similar, and scales linearly with data block size. Since the performance of the migration mechanism is on par with that of an L2 cache, the implementation simulated in my work has no data caches and relies instead on multithreading and the migration mechanism to hide and reduce access latencies.

Verb Classes and Alternations in Bangla, German, English, and Korean

In this report, we investigate the relationship between the semantic and syntactic properties of verbs. Our work is based on the English Verb Classes and Alternations of (Levin, 1993). We explore how these classes are manifested in other languages, in particular, in Bangla, German, and Korean. Our report includes a survey and classification of several hundred verbs from these languages into the cross-linguistic equivalents of Levin's classes. We also explore ways in which our findings may be used to enhance WordNet in two ways: making the English syntactic information of WordNet more fine-grained, and making WordNet multilingual.

Interactions between grain size and composition of sediments: two examples

Two contrasting case studies of sediment and detrital mineral composition are investigated in order to outline interactions between chemical composition and grain size. Modern glacial sediments exhibit a strong dependence of the two parameters due to the preferential enrichment of mafic minerals, especially biotite, in the fine-grained fractions. On the other hand, the composition of detrital heavy minerals (here: rutile) appears to be not systematically related to grain-size, but is strongly controlled by location, i.e. the petrology of the source rocks of detrital grains. This supports the use of rutile as a well-suited tracer mineral for provenance studies. The results further suggest that (i) interpretations derived from whole-rock sediment geochemistry should be flanked by grain-size observations, and (ii) a more sound statistical evaluation of these interactions require the development of new tailor-made statistical tools to deal with such so-called two-way compositions

Predicting sense of community and participation by applying machine learning to open government data

Community capacity is used to monitor socio-economic development. It is composed of a number of dimensions, which can be measured to understand the possible issues in the implementation of a policy or the outcome of a project targeting a community. Measuring community capacity dimensions is usually expensive and time consuming, requiring locally organised surveys. Therefore, we investigate a technique to estimate them by applying the Random Forests algorithm on secondary open government data. This research focuses on the prediction of measures for two dimensions: sense of community and participation. The most important variables for this prediction were determined. The variables included in the datasets used to train the predictive models complied with two criteria: nationwide availability; sufficiently fine-grained geographic breakdown, i.e. neighbourhood level. The models explained 77% of the sense of community measures and 63% of participation. Due to the low geographic detail of the outcome measures available, further research is required to apply the predictive models to a neighbourhood level. The variables that were found to be more determinant for prediction were only partially in agreement with the factors that, according to the social science literature consulted, are the most influential for sense of community and participation. This finding should be further investigated from a social science perspective, in order to be understood in depth.

Annual textural banding in Holocene estuarine silts, Severn Estuary Levels (SW Britain): patterns, cause and implications

A high-resolution textural study has been made of laminated and banded estuarine silts exposed intertidally at representative localities and horizons in the Holocene deposits of the Severn Estuary Levels. The laminae, on a submillimetre to millimetre scale, are sharp-based, graded couplets formed of a lower silty part overlain by a finer-textured clayey element. The centimetre- to decimetre-scale banding is formed of laminae in alternating, gradually intergrading sets of relatively coarse and relative fine-grained examples. At outcrop in the field, the banding is recognizable because the coarse sets prove to be recessive to varying degrees under the influence of weathering and current action. Independent evidence at two localities points toward an annual origin for the banding; at a third it arose during part of what appears to have been a relatively short period. Quantified physical arguments suggest that the textural banding is a response of suspended fine sediment to marked seasonal changes in sea temperature and windiness. The banded silts occur in four distinct stratigraphical contexts and record high deposition rates (order 0.01-0.1 m/yr). Because physical factors determine their textures, the silts potentially afford insights in all contexts into aspects of changing Holocene climatic conditions. In one context, the thickness of the bands points to high (order 0.01-0.1 m/yr) but comparatively short-lived (order 10s-100s yrs) rates of relative water-level rise. In the others, however, the banding has no implications for sea-level behaviour, and simply records gross environmental disequilibrium, for example, the recovery of mudflats/marshes after an erosional episode. Similarly, because on account of their rapid accumulation the banded silts preserve animal and human tracks and trackways especially well, they provide an archive of animal and human behaviour in the area during the Holocene.

Seasonality of modern pollen and sediment deposition in an estuarine context: the Severn Estuary Levels, southwest England

Recent sedimentological and palynological research on subfossil Holocene banded sediments from the Severn Estuary Levels suggested seasonality of deposition, registered by variations in mineral grain-size and pollen assemblages between different parts of the bands. Here we provide data that strengthen this interpretation from sampling of modern sediments and pollen deposition on an active mudflat and saltmarsh on the margin of the Severn Estuary, and comparison with a vegetation survey and contemporary records of climate, river and tidal regimes. The results of grain-size analysis indicate deposition of comparatively coarse-grained silts during the relatively cool and windy conditions of winter and comparatively fine-grained sediments during relatively warm and calm summer months. Pollen analysis demonstrates the significance of long-term storage of pollen grains and fern spores in the estuarine waterbody, superimposed on which seasonal variations in pollen inputs from local and regional vegetation remain detectable. Copyright (C) 2007 John Wiley & Sons, Ltd.

Seasonal deposition of Holocene banded sediments in the Severn Estuary Levels (southwest Britain): palynological and sedimentological evidence

Banded sediments outcrop widely in the intertidal zone of the Severn Estuary and have been suggested, on the basis of textural analysis, to have formed in response to seasonal variations in sea temperature and windiness (Holocene, 14 (2004) 536). Here palynological and sedimentological analyses of banded sediments of mid-Holocene date from Gold Cliff, on the Welsh side of the Severn Estuary, are combined to test and further develop the hypothesis of seasonal deposition. Pollen percentage and concentration data are presented from a short sequence of bands to establish whether textural variations in the bands coincide with variations in pollen content reflecting seasonal flowering patterns. It is shown that fine-grained band parts contain higher total pollen concentrations, and a higher proportion of pollen from late spring- to summer-flowering plants, than coarse-grained band parts. Pollen in the coarser deposits appears primarily to reflect deposition from the buffering `reservoir' of suspended pollen in the estuarine water-body and from rivers, when there is little pollen in the air in winter, while the finer sediments contain pollen deposited from the atmosphere during the flowering season, superimposed on these `background' sources. The potential of such deposits for refining chronologies and identifying seasonality of coastal processes is noted, and the results of charcoal particle analysis of the bands presented as an example of how they have the potential to shed light on seasonal and annual patterns of human activity. (C) 2004 Elsevier Ltd. All rights reserved.

The Dubawnt Lake palaeo-ice stream: evidence for dynamic ics sheet behaviour on the Canadian Shield and insights regarding the controls on ice-stream location and vigour

We report evidence for a major ice stream that operated over the northwestern Canadian Shield in the Keewatin Sector of the Laurentide Ice Sheet during the last deglaciation 9000-8200 (uncalibrated) yr BP. It is reconstructed at 450 km in length, 140 km in width, and had an estimated catchment area of 190000 km. Mapping from satellite imagery reveals a suite of bedforms ('flow-set') characterized by a highly convergent onset zone, abrupt lateral margins, and where flow was presumed to have been fastest, a remarkably coherent pattern of mega-scale glacial lineations with lengths approaching 13 km and elongation ratios in excess of 40:1. Spatial variations in bedform elongation within the flow-set match the expected velocity field of a terrestrial ice stream. The flow pattern does not appear to be steered by topography and its location on the hard bedrock of the Canadian Shield is surprising. A soft sedimentary basin may have influenced ice-stream activity by lubricating the bed over the downstream crystalline bedrock, but it is unlikely that it operated over a pervasively deforming till layer. The location of the ice stream challenges the view that they only arise in deep bedrock troughs or over thick deposits of 'soft' fine-grained sediments. We speculate that fast ice flow may have been triggered when a steep ice sheet surface gradient with high driving stresses contacted a proglacial lake. An increase in velocity through calving could have propagated fast ice flow upstream (in the vicinity of the Keewatin Ice Divide) through a series of thermomechanical feedback mechanisms. It exerted a considerable impact on the Laurentide Ice Sheet, forcing the demise of one of the last major ice centres.