Avec plus de 400 000 ha, le douglas (Pseudotsuga Menziesii (Mirb.) Franco) est l’une des essences les plus plantées en France. Originaire de l’ouest de l’Amérique du Nord, cette essence introduite est appréciée des gestionnaires forestiers pour sa croissance rapide et la qualité de son bois. Cependant ses performances de productivité pourraient être compromises dans le contexte d’augmentation de la fréquence des sécheresses. Suite à la sécheresse exceptionnelle de 2003, le douglas a en effet connu des dysfonctionnements importants (mortalité, pertes foliaires, réduction de croissance …) et durables marquant l’entrée dans une phase de dépérissement. Les objectifs de ce travail sont (1) de vérifier si la sécheresse est l’aléa induisant le dépérissement, (2) de déterminer les facteurs écologiques et sylvicoles de vulnérabilité à la sécheresse et (3) de contribuer à l’exploration de la variabilité génétique de la réponse à la sécheresse au travers de l’étude de provenances issues de l’aire naturelle. L’analyse des signalements du Département de la Santé de la Forêt a montré que les deux principales régions affectées par ces dépérissements post 2003 sont la Bourgogne et le nord-est de la région Midi-Pyrénées. L’étude dendro-écologique menée dans ces deux régions nous a permis de démontrer (1) la très forte sensibilité de la croissance radiale à l’intensité du déficit hydrique du sol, (2) que si la sécheresse exceptionnelle de 2003 est l’aléa déclenchant du dépérissement, les sécheresses récurrentes entre 2003 et 2006 ont induit une perte de croissance radiale prolongée, (3) que les sols à faible réserve utile constitue un facteur de vulnérabilité au dépérissement. La fertilité minérale du sol évaluée par bio-indication apparaît comme un facteur clé de la récupération de la croissance. Lors de l’étude génétique, aucune différence de croissance en réponse à la sécheresse n’a pu être mise en évidence entre les provenances Washington et Oregon. L’ensemble de ces résultats permet de proposer des recommandations aux gestionnaires pour réduire les risques de dépérissement induits par la sécheresse. / With more than 400 000 ha, Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) is one of the most widely planted species in France. This introduced species native of western North America, is forest managers appreciated for its rapid growth and quality of its wood. However, its productivity performance could be compromised in the context of increased frequency of droughts. Following the exceptional drought of 2003, Douglas has indeed experienced major and durable shortcomings (mortality, leaf loss, reduced growth ...) marking the entry into a phase of decline. The objectives of this work are (1) to check if the hazard inducing decline is drought, (2) to determine the ecological and silvicultural factors of vulnerability to drought and (3) contribute to the exploration of the variability genetic response to drought through the study of provenances from the natural range. Analysis of reports of the Department of Health Forest showed that the two main areas affected by the dieback are post 2003 Burgundy and northeast of the Midi-Pyrenees. The dendro-ecological study conducted in these two regions allowed us to demonstrate (1) the high sensitivity of radial growth in the intensity of soil moisture deficit, (2) if the exceptional drought of 2003 is the decline inducing hazard, recurrent droughts between 2003 and 2006 induced a prolonged loss of radial growth, (3) that soils with low reserves are a factor of vulnerability to dieback. Mineral soil fertility assessed by bio-indication appears as a key factor in the recovery of growth. In the genetic study, no difference in growth in response to drought could be demonstrated between Washington and Oregon provenances. All these results allow us to make recommendations to managers to reduce the risk of dieback induced by drought.

No description available.

The Beaverhead Group records coarse-grained, conglomeratic deposition in the northwestern foredeep of the Cordilleran foreland basin. In the northeastern portion of the study area, it unconformably overlies and is deformed by the Laramide-style Blacktail-Snowcrest uplift. To the west, it is deformed by and structurally juxtaposed against Paleozoic and Mesozoic passive margin strata in the Sevier-style fold-thrust belt. Previous work on limited palynomorph samples suggests Coniacian-Campanian (~89-72 Ma) depositional ages while structural and stratigraphic relationships additionally suggest Maastrichtian-Lower Cenozoic depositional ages. Previous work based on clast compositions implies that units involved in deformation related to both the Sevier thrust belt and Laramide-style Blacktail-Snowcrest uplift were the primary sediment sources to the Beaverhead Group. This study aims to better define the depositional age and provenance of the Beaverhead Group by utilizing U-Pb dating of detrital zircons in combination with conglomerate clast compositions and sandstone petrography. Maximum depositional ages based on the ages of youngest single grains range from ~83-66 Ma (Campanian-Maastrichtian). Provenance analysis for various units of the Beaverhead Group suggest local and/or distal sediment sources, with the former encompassing the Blacktail-Snowcrest uplift and local portions of the Sevier thrust belt and the latter including distal portions of the Sevier thrust belt. Maximum depositional ages in conjunction with provenance interpretations require that the Blacktail-Snowcrest uplift was actively exhuming at ~81 Ma and that the Sevier thrust belt was locally active from ~83-66 Ma. Distally sourced sediments from the Belt Supergroup of Idaho suggest that a paleoriver system connected regional sources to Beaverhead Group depocenters from at least ~83-66 Ma.

Scientists often need to know how data was derived in addition to what it is. The detailed tracking of data transformation or provenance allows result reproducibility, knowledge reuse and data analysis. Scientific workflows are increasingly being used to represent provenance as they are capable of recording complicated processes at various levels of detail. In context of knowledge reuse and sharing; search technology is of paramount importance specially considering the huge and ever increasing amount of scientific data. It is computationally hard to produce a single exact answer to the user's query due to sheer volume and complicated structure of provenance.  One solution to this difficult problem is to produce a list of candidate matches and let user select the most relevant result. Here search result presentation becomes very important as the user is required to make the final decision by looking at the workflows in the result list. Presentation of these candidate matches needs to be brief, precise, clear and revealing. This is a challenging task in case of workflows as they contain textual content as well as graphical structure. Current workflow search engines such as Yahoo Pipes! or myExperiment ignore the actual workflow specification and use metadata to create summaries. Workflows which lack metadata do not make good summaries even if they are useful and relevant as search criteria. This work investigates the possibility of creating meaningful and usable summaries or snippets based on structure and specification of workflows. We shall  (1) present relevant published work done regarding snippet building techniques (2) explain how we mapped current techniques to our work (3) describe how we identified techniques from interface design theory in order to make usable graphical interface (4) present implementation of two new algorithms for workflow graph compression and their complexity analysis (5) identify future work in our implementation and outline open research problems in snippet building field.

This dissertation aims to provide insight into the relationships between environmental factors and the organization of quartz technology in northern Manitoba by evaluating the contribution of large pegmatite quarries to quartz economies around Granville and Southern Indian Lakes. Secondary ion mass spectrometry (SIMS) quantification of trace element (Ti, Ge, U, Th) concentrations and Pb isotope ratios was used to characterize large sources of pegmatite quartz exploited by toolmakers in the Granville Lake and Lac La Ronge regions of northern Manitoba and Saskatchewan, respectively. The same technique was applied to a sample of formal quartz tools from the Churchill River Diversion Archaeological Project (CRDAP) study area in northern Manitoba. Quarry and artifact results were compared. The results of this analysis indicate: 1) characterized pegmatite quartz sources in the Granville Lake district likely played a significant role in quartz economies in the Churchill River basin of northern Manitoba, 2) toolmakers in the study area had large lithic procurement ranges, and 3) lithic resource stress contributed to the selection of technological strategies in the Churchill River basin.

This dissertation aims to provide insight into the relationships between environmental factors and the organization of quartz technology in northern Manitoba by evaluating the contribution of large pegmatite quarries to quartz economies around Granville and Southern Indian Lakes. Secondary ion mass spectrometry (SIMS) quantification of trace element (Ti, Ge, U, Th) concentrations and Pb isotope ratios was used to characterize large sources of pegmatite quartz exploited by toolmakers in the Granville Lake and Lac La Ronge regions of northern Manitoba and Saskatchewan, respectively. The same technique was applied to a sample of formal quartz tools from the Churchill River Diversion Archaeological Project (CRDAP) study area in northern Manitoba. Quarry and artifact results were compared. The results of this analysis indicate: 1) characterized pegmatite quartz sources in the Granville Lake district likely played a significant role in quartz economies in the Churchill River basin of northern Manitoba, 2) toolmakers in the study area had large lithic procurement ranges, and 3) lithic resource stress contributed to the selection of technological strategies in the Churchill River basin.

abstract: A statement appearing in social media provides a very significant challenge for determining the provenance of the statement. Provenance describes the origin, custody, and ownership of something. Most statements appearing in social media are not published with corresponding provenance data. However, the same characteristics that make the social media environment challenging, including the massive amounts of data available, large numbers of users, and a highly dynamic environment, provide unique and untapped opportunities for solving the provenance problem for social media. Current approaches for tracking provenance data do not scale for online social media and consequently there is a gap in provenance methodologies and technologies providing exciting research opportunities. The guiding vision is the use of social media information itself to realize a useful amount of provenance data for information in social media. This departs from traditional approaches for data provenance which rely on a central store of provenance information. The contemporary online social media environment is an enormous and constantly updated "central store" that can be mined for provenance information that is not readily made available to the average social media user. This research introduces an approach and builds a foundation aimed at realizing a provenance data capability for social media users that is not accessible today. / Dissertation/Thesis / Ph.D. Computer Science 2011

We’re witnessing the era of Data-Oriented Science, where investigations routinely involve computational data analysis. The research lifecycle has now become more elaborate to support the sharing and re-use of scientific data. To establish the veracity of shared data, scientific communities aim for systematising 1) the process of analysing data, and, 2) the reporting of analyses and results. Scientific workflows are a prominent mechanism for systematising analyses by encoding them as automated processes and documenting process executions with Workflow Provenance. Meanwhile, systematic reporting calls for discipline-specific Experimental Metadata to be provided outlining the context of data analysis such as source/reference datasets and community resources used, analytical methods and their parameter settings. A natural expectation would be that investigations, which adopt a systematic, workflow-based approach to the analysis can be advantageous at the time of reporting. This premise holds weakly. While workflow provenance supports streamlined enactment of analyses, their auditability and verifiability, we conjecture that it has limited contribution to reporting. This dissertation focuses on eliciting the apparent disconnect of Workflow Provenance and Experimental Metadata as the provenance gap. We identify complexity, mixed granularity, and genericity as characteristics of workflow provenance that underlie this gap. In response we develop techniques for provenance abstraction, analysis and annotation. We argue that workflow provenance is accompanied with implicit information, that can be made explicit to inform these techniques. Through empirical evidence we show that workflow steps have common functional characteristics, which we capture in a taxonomy of Workflow Motifs. We show how formally defined Graph Transformations can exploit Motifs to identify causes of complexity in workflows and abstract them to structurally simpler forms. We build on insight from prior research to show how execution and provenance collection behaviour of a workflow system can anticipate the granularity characteristics of provenance. We provide declarative anticipatory rules for the static-analysis of workflows of the Taverna system. We observe that scientific context is often available in embedded form in data and argue that data can be lifted to become metadata by discipline-specific metadata extractors. We outline a framework, that can be plugged with extractors and provide operators that encapsulate generic procedures to annotate workflow provenance. We implement our techniques with technology-independent provenance models and we showcase their benefit using real-world workflows.

Data provenance refers to the lineage or pedigree of data, including information such as its origin and key events that affect it over the course of its lifecycle. In recent years, provenance has become increasingly important as more and more people are using data that they themselves did not generate. Tracking data provenance helps ensure that data provided by many different providers and sources can be trusted and used appropriately. Data provenance also has several other critical uses, including data quality assessment, generating data replication recipes, data security management, etc.One of the major objectives of our research is to investigate the semantics or meaning of data provenance. We describe a generic ontology of data provenance called the W7 model that represents the semantics of data provenance. Formalized in the conceptual graph formalism, the W7 model represents provenance as a combination of seven interconnected elements including "what," "when," "where," "how," "who," "which" and "why." The W7 model is designed to be general and comprehensive enough to cover a broad range of provenance-related vocabularies. However, the W7 model alone, no matter how comprehensive it is, is insufficient for capturing all domain-specific provenance requirements. We hence present a novel approach to developing domain ontologies of provenance. This approach relies on various conceptual graph mechanisms, including schema definitions and canonical formation rules, and enables us to easily adapt and extend the W7 model to develop domain ontologies of provenance. The W7 model for data provenance has been widely adopted and adapted for use within Raytheon Missile Systems and the iPlant Collaborative, as well as the US Army's ATRAP IV (Asymmetric Threat Response and Analysis Program) system.We also developed a domain ontology of provenance for Wikipedia based on the W7 model. This domain ontology enables us to extract provenance for each Wikipedia article. We present a study in which we use their provenance to assess the quality of Wikipedia articles. Assessing and guaranteeing data quality has become a critical concern that, to a large extent, determines the future success and survival of Wikipedia since the quality of Wikipedia has been continuously called into question due to various incidents of vandalism and misinformation since its launch in 2001. Our study shows that the quality of Wikipedia articles depends not only on the different types of contributors but also on how they collaborate. We identify a number of contributor roles based on the provenance. Based on the roles and provenance, our research identifies several collaboration patterns that are preferable or detrimental for data quality, thus providing insights for designing tools and mechanisms to improve Wikipedia article quality.

No description available.