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Isolation and characterization of two canine melanoma cell lines new models for comparative oncology
No full textInternational audienceBackground: Metastatic melanoma is one of the most aggressive forms of cancer in humans. Among its types, mucosal melanomas represent one of the most highly metastatic and aggressive forms, with a very poor prognosis. Because they are rare in Caucasian individuals, unlike cutaneous melanomas, there has been fewer epidemiological, clinical and genetic evaluation of mucosal melanomas. Moreover, the lack of predictive models fully reproducing the pathogenesis and molecular alterations of mucosal melanoma makes its treatment challenging. Interestingly, dogs are frequently affected by melanomas of the oral cavity that are characterized, as their human counterparts, by focal infiltration, recurrence, and metastasis to regional lymph nodes, lungs and other organs. In dogs, some particular breeds are at high risk, suggesting a specific genetic background and strong genetic drivers. Altogether, the striking homologies in clinical presentation, histopathological features, and overall biology between human and canine mucosal melanomas make dogs invaluable natural models with which to investigate tumor development, including tumor aetiology, and develop tailored treatments.Methods: We developed and characterized two canine oral melanoma cell lines from tumors isolated from dog patients with distinct clinical profiles; with and without lung metastases. The cells were characterized using immunohistochemistry, pharmacology and genetic studies.Results: We have developed and immunohistochemically, genetically, and pharmacologically characterized. Two cell lines (Ocr_OCMM1X and Ocr_OCMM2X) were produced through mouse xenografts originating from two clinically contrasting melanomas of the oral cavity. Their exhaustive characterization showed two distinct biological and genetic profiles that are potentially linked to the stage of malignancy at the time of diagnosis and sample collection of each melanoma case. These cell lines thus constitute relevant tools with which to perform genetic and drug screening analyses for a better understanding of mucosal melanomas in dogs and humans.Conclusions: The aim of this study was to establish and characterize xenograft-derived canine melanoma cell lines with different morphologies, genetic features and pharmacological sensitivities that constitute good predictive models for comparative oncology. These cell lines are relevant tools to advance the use of canine mucosal melanomas as natural models for the benefit of both veterinary and human medicine
Motivation as a Mediator of the Relation Between Cognitive Reserve and Cognitive Performance
No full textInternational audienceInterindividual differences in cognitive aging may be explained by differences in cognitive reserve (CR) that are built-up across the lifespan. A plausible but under-researched mechanism for these differences is that CR helps compensating cognitive decline by enhancing motivation to cope with challenging cognitive situations. Theories of motivation on cognition suggest that perceived capacity and intrinsic motivation may be key mediators in this respect
The emergence of the grammatical paradigm of nominal determiners in French and in Romance: Comparative and diachronic perspectives
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Predicting and Assessing Student Motivation and Autonomy in a Distance Learning Context
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Natural Steganography in JPEG Compressed Images
No full textInternational audienceIn natural steganography, the secret message is hidden by adding to the cover image a noise signal that mimics the het-eroscedastic noise introduced naturally during acquisition. The method requires the cover image to be available in its RAW form (the sensor capture). To bring this idea closer to a practical embedding method, in this paper we embed the message in quantized DCT coefficients of a JPEG file by adding independent realiza-tions of the heteroscedastic noise to pixels to make the embedding resemble the same cover image acquired at a larger sensor ISO setting (the so-called cover source switch). To demonstrate the feasibility and practicality of the proposed method and to validate our simplifying assumptions, we work with two digital cameras , one using a monochrome sensor and a second one equipped with a color sensor. We then explore several versions of the embedding algorithm depending on the model of the added noise in the DCT domain and the possible use of demosaicking to convert the raw image values. These experiments indicate that the demo-saicking step has a significant impact on statistical detectability for high JPEG quality factors when making independent embedding changes to DCT coefficients. Additionally, for monochrome sensors or low JPEG quality factors very large payload can be embedded with high empirical security
Edge detection from Bayer color filter array image
No full textInternational audienceSingle-sensor color cameras primarily form images through a color filter array laid over the sensor. The acquired raw data represent a single color component per pixel and usually undergo demosaicking to form fully defined color images. This, however, produces artifacts that may affect the performance of low-level processing tasks applied to such estimated images. We instead propose to directly use raw data to estimate the image partial derivatives for edge detection. Considering luminance- and color-based approaches based on Deriche filters, we show that schemes using raw data may provide as accurate edge detection results as classical demosaicking-based ones at much reduced computational cost
Un parcours audacieux : Hésiode de l’Enûma elish au Paradis perdu
No full textInternational audienceÀ propos de : S. Scully, Hesiod’s Theogony. From Near Eastern Creation Myths to Paradise Lost. – Oxford : University Press, 2015. – X+268 p. : bibliogr., index. – (Oxford Monographs on Classical Archaeology). – ISBN : 978.0.19.025396.7
Master’s theses and open scholarship: a case study
No full textInternational audiencePurpose-This paper aims to show how Master's theses can contribute to open scholarship and give reasons why this should be done.Design/methodology/approach-The paper provides an overview of published studies and, based on the experience at the University of Lille (France), describes some essential aspects for the processing and valorization of these documents in the academic cloud, as a contribution of open scholarship.Findings-Because of their number and diversity, collections of Masters' theses in open repositories could be an excellent showcase for the universities' Master programs and research. They could also offer interesting and large samples for content analysis, citation analysis and text and data mining (TDM). However, some issues need attention, above all intellectual property, quality and preservation. Quality is crucial, and the paper describes how the Lille project proceeds to assure sufficient quality and right clearance, and why the project shifted from students' self-archiving to a digital library collection in the academic cloud, run by faculty and information professionals. The paper presents also some usage statistics to illustrate the potential, global impact of such a collection.Practical implications-The paper provides helpful and empirical evidence and insight for those who want to develop the dissemination of Master's theses via open repositories.Originality/value-In the context of open scholarship, only few studies deal with Master's theses, and this paper is the only recent reference that brings together a review of other papers and a case study with empirical evidence