Contribution à la connaissance du phytoplankton de l'Atlantique nord-est et de la Mer du Nord

This study shows that the principal ecological factors influencing the studied area are light, determined by very unequal day lengths, the wind, provoking a fairly homogenically mixed layer of microscopic organisms, and water depth, which in correlation with the proximity of the coast line determined the nutrient salinity concentration. The floral study allowed the determination of algal concentration in the different zones during different periods of the year, and also the quantitative and qualitative photosynthetic activity fluctuations of several florules. The study also resulted in a zonal and chronological delimitation of a large number of species of the studied area. The degressive lists, based on the mean algal frequency, showed the photosynthetically important species for each zone. Finally, the urgent necessity of large enough outtakes is shown through the phenomenon of explosive blooms of certain species

Silencing Indigenous Knowledge Systems: Analysis of Canadian Educational, Legal and Administrative Practice

As a result of the Truth and Reconciliation Commission of Canada (or TRCC, 2015a, 2015b), calls to action concerning education and law reform have been made. Currently, there is an increase in reconciliation discourse in law, healthcare and education policy, curricula and pedagogy. In Canada, efforts to decolonize institutional structures compel scholars and activists to highlight the imperative of critical analysis of identity and place in answering the calls to action. Although it was developed by the Ministry of Education for the province of Ontario, more than a decade ago, prior to the TRCC, the First Nations, Métis, and Inuit Education Policy Framework continues to inform policy and administrative procedures. Informed by Indigenous knowledge systems embedded in restorative justice and peace-building practices, this paper presents a critical analysis of the First Nations, Métis, and Inuit Education Policy Framework (2007) and finds evidence resembling discursive settler-colonial patterns of Indigenous erasure through the practice of silencing Indigenous participation and voice. Through this critical analysis, several themes emerged including colonialism, survivance, patriarchy, self-identification, notions of education, assessment, and “us versus them” binary narratives. In response, this paper argues for a trans-systemic and transdisciplinary approach to the critical analysis of discursive patterns of silencing and erasure in policy, law reform, and administrative processes. Further, through deepening interpretations and understandings of Indigenous theory and knowledge systems, it may be possible for settler-colonial stakeholders to more acutely discern the impact of settler-colonialism embedded in education, policy, administration, and legal discourses. These findings have implications for educators and administrators as well as administrative, law and policy reform. 

3D Quantification of Ultrasound Images: Application to Mouse Embryo Imaging In Vivo

International audienceHigh frequency ultrasound imaging has become an effective tool for anatomical mice studies. This work is focused on 3D quantification of mouse embryo development to extract pertinent information of its evolution. A series of B-Scan ultrasound images was acquired at different spatial positions along the embryo. A 3D deformable model was used to segment the images. A pregnant female mouse at embryonic day 14.5 was imaged with an ATL HDI 5000, 7-15MHz linear array. The probe was moved by a step by step motor along the abdomen of the mouse. 3D segmentation results are presented including volume quantification of the embryo

Creating value in ecosystems: Crossing the chasm between, knowledge and business ecosystems

Policy makers take initiatives to stimulate knowledge ecosystems in technology hotspots. It is implicitly assumed that these ecosystems will lead to value networks through which the participating companies can realize a competitive advantage. Value networks refer to business ecosystems where the value proposition is offered by a group of companies which are mutually complementary. The strategy literature suggests that business ecosystems lead to competitive advantages for each of the partners in the ecosystem. Based on a unique hand-collected database of 138 innovative start-ups in the region of Flanders, we analyze the knowledge and business ecosystem and the financial support network. We find that the knowledge ecosystem is well structured and concentrated around a number of central actors while the business ecosystem is almost non-existent at the local level. Further, we find that the financial support network is almost 100% publicly backed and fails to bridge the knowledge and business ecosystem. The implications for policy makers who tend to focus on the development of local ecosystems are discussed

Multiscale optical flow computation from the monogenic signal

National audienceWe have developed an algorithm for the estimation of cardiac motion from medical images. The algorithm exploits monogenic signal theory, recently introduced as an N-dimensional generalization of the analytic signal. The displacement is computed locally by assuming the conservation of the monogenic phase over time. A local affine displacement model replaces the standard translation model to account for more complex motions as contraction/expansion and shear. A coarse-to-fine B-spline scheme allows a robust and effective computation of the models parameters and a pyramidal refinement scheme helps handle large motions. Robustness against noise is increased by replacing the standard pointwise computation of the monogenic orientation with a more robust least-squares orientation estimate. This paper reviews the results obtained on simulated cardiac images from different modalities, namely 2D and 3D cardiac ultrasound and tagged magnetic resonance. We also show how the proposed algorithm represents a valuable alternative to state-of-the-art algorithms in the respective fields

A mutual reference shape based on information theory

International audienceIn this paper, we propose to consider the estimation of a refer-ence shape from a set of different segmentation results using both active contours and information theory. The reference shape is defined as the minimum of a criterion that benefits from both the mutual information and the joint entropy of the input segmentations and called a mutual shape. This energy criterion is here justified using similarities between informa-tion theory quantities and area measures, and presented in a continuous variational framework. This framework brings out some interesting evaluation measures such as the speci-ficity and sensitivity. In order to solve this shape optimization problem, shape derivatives are computed for each term of the criterion and interpreted as an evolution equation of an active contour. Some synthetical examples allow us to cast the light on the difference between our mutual shape and an average shape. Our framework has been considered for the estimation of a mutual shape for the evaluation of cardiac segmentation methods in MRI

Myocardial Extracellular Volume Estimation by CMR Predicts Functional Recovery Following Acute MI

Objectives: In the setting of reperfused acute myocardial infarction (AMI), the authors sought to compare prediction of contractile recovery by infarct extracellular volume (ECV), as measured by T1-mapping cardiac magnetic resonance (CMR), with late gadolinium enhancement (LGE) transmural extent. Background: The transmural extent of myocardial infarction as assessed by LGE CMR is a strong predictor of functional recovery, but accuracy of the technique may be reduced in AMI. ECV mapping by CMR can provide a continuous measure associated with the severity of tissue damage within infarcted myocardium. Methods: Thirty-nine patients underwent acute (day 2) and convalescent (3 months) CMR scans following AMI. Cine imaging, tissue tagging, T2-weighted imaging, modified Look-Locker inversion T1 mapping natively and 15 min post–gadolinium-contrast administration, and LGE imaging were performed. The ability of acute infarct ECV and acute transmural extent of LGE to predict convalescent wall motion, ejection fraction (EF), and strain were compared per-segment and per-patient. Results: Per-segment, acute ECV and LGE transmural extent were associated with convalescent wall motion score (p < 0.01; p < 0.01, respectively). ECV had higher accuracy than LGE extent to predict improved wall motion (area under receiver-operating characteristics curve 0.77 vs. 0.66; p = 0.02). Infarct ECV ≤0.5 had sensitivity 81% and specificity 65% for prediction of improvement in segmental function; LGE transmural extent ≤0.5 had sensitivity 61% and specificity 71%. Per-patient, ECV and LGE correlated with convalescent wall motion score (r = 0.45; p < 0.01; r = 0.41; p = 0.02, respectively) and convalescent EF (p < 0.01; p = 0.04). ECV and LGE extent were not significantly correlated (r = 0.34; p = 0.07). In multivariable linear regression analysis, acute infarct ECV was independently associated with convalescent infarct strain and EF (p = 0.03; p = 0.04), whereas LGE was not (p = 0.29; p = 0.24). Conclusions: Acute infarct ECV in reperfused AMI can complement LGE assessment as an additional predictor of regional and global LV functional recovery that is independent of transmural extent of infarction

Multi-modality image simulation with the Virtual Imaging Platform: Illustration on cardiac echography and MRI

International audienceMedical image simulation is useful for biological modeling, image analysis, and designing new imaging devices but it is not widely available due to the complexity of simulators, the scarcity of object models, and the heaviness of the associated computations. This paper presents the Virtual Imaging Platform, an openly-accessible web platform for multi-modality image simulation. The integration of simulators and models is described and exemplified on simulated cardiac MRIs and ultrasonic images

Assessing Communities of Practice in health policy : A conceptual framework as a first step towards empirical research

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