Algorithmes de recommandation musicale

Ce mémoire est composé de trois articles qui s’unissent sous le thème de la recommandation musicale à grande échelle. Nous présentons d’abord une méthode pour effectuer des recommandations musicales en récoltant des étiquettes (tags) décrivant les items et en utilisant cette aura textuelle pour déterminer leur similarité. En plus d’effectuer des recommandations qui sont transparentes et personnalisables, notre méthode, basée sur le contenu, n’est pas victime des problèmes dont souffrent les systèmes de filtrage collaboratif, comme le problème du démarrage à froid (cold start problem). Nous présentons ensuite un algorithme d’apprentissage automatique qui applique des étiquettes à des chansons à partir d’attributs extraits de leur fichier audio. L’ensemble de données que nous utilisons est construit à partir d’une très grande quantité de données sociales provenant du site Last.fm. Nous présentons finalement un algorithme de génération automatique de liste d’écoute personnalisable qui apprend un espace de similarité musical à partir d’attributs audio extraits de chansons jouées dans des listes d’écoute de stations de radio commerciale. En plus d’utiliser cet espace de similarité, notre système prend aussi en compte un nuage d’étiquettes que l’utilisateur est en mesure de manipuler, ce qui lui permet de décrire de manière abstraite la sorte de musique qu’il désire écouter.This thesis is composed of three papers which unite under the general theme of large-scale music recommendation. The first paper presents a recommendation technique that works by collecting text descriptions of items and using this textual aura to compute the similarity between them using techniques drawn from information retrieval. We show how this representation can be used to explain the similarities between items using terms from the textual aura and further how it can be used to steer the recommender. Because our system is content-based, it is not victim of the usual problems associated with collaborative filtering recommenders like the cold start problem. The second paper presents a machine learning model which automatically applies tags to music. The model uses features extracted from the audio files and was trained on a very large data set constructed with social data from the online community Last.fm. The third paper presents an approach to generating steerable playlists. We first demonstrate a method for learning song transition probabilities from audio features extracted from songs played in professional radio station playlists. We then show that by using this learnt similarity function as a prior, we are able to generate steerable playlists by choosing the next song to play not simply based on that prior, but on a tag cloud that the user is able to manipulate to express the high-level characteristics of the music he wishes to listen to

Instantaneous heat transfers at the impact of a droplet onto a hot surface in the film boiling regime

[EN] Heat and mass transfers at the impact of a droplet onto a hot solid surface are investigated experimentally. Millimetersized water droplets impinges onto a perfectly flat sapphire surface heated at 600°C. The temperature of the liquid inside the droplet is measured using the two-color laser-induced fluorescence (2cLIF) technique. Water is seeded with a temperature-sensitive fluorescent dye, while a nanosecond pulsed laser is used for the excitation of the fluorescence. The ratio of fluorescence signal detected in two appropriate spectral bands allows to determine the liquid temperature. One advantage of this non-intrusive optical technique is that it eliminates adverse effects associated with signal variations caused by droplet shape during its impact. In parallel, the temperature of the solid surface is characterized using infrared thermography. The latter measurements are made possible by the deposition of a nanosize coating of titanium aluminium nitride (TiAlN) on the upper surface of the sapphire window. Thanks to the high frame rate of the IR camera, the time evolution of the heat flux distribution at the solid surface can be reconstructed. A comparison of IR and 2cLIF techniques enable to correlate the heating of the liquid with the cooling of the wall. This reveals that most of the heat removed from the solid surface is devoted to the heating of the liquid, the energy used for liquid vaporization being significantly lower.The authors acknowledge the financial support of the Lorraine region through the CPER ENERBATIN projet.Chaze, W.; Castanet, G.; Caballina, O.; Maillet, D.; Pierson, J.; Lemoine, F. (2017). Instantaneous heat transfers at the impact of a droplet onto a hot surface in the film boiling regime. En Ilass Europe. 28th european conference on Liquid Atomization and Spray Systems. Editorial Universitat Politècnica de València. 282-289. https://doi.org/10.4995/ILASS2017.2017.4636OCS28228

Complete amino acid sequence of a human platelet proteoglycan

AbstractThe primary structure of a human platelet proteoglycan (P.PG) core was established by a combination of amino acid sequence analysis and cDNA cloning. The deduced 131 amino acid long protein contains eight Ser-Gly repeats. The significance of homologies observed between P.PG and promyelocytic leukemia cell line proteoglycans is discussed

Caffeic Acid Phenethyl Ester and Its Amide Analogue Are Potent Inhibitors of Leukotriene Biosynthesis in Human Polymorphonuclear Leukocytes

BACKGROUND: 5-lipoxygenase (5-LO) catalyses the transformation of arachidonic acid (AA) into leukotrienes (LTs), which are important lipid mediators of inflammation. LTs have been directly implicated in inflammatory diseases like asthma, atherosclerosis and rheumatoid arthritis; therefore inhibition of LT biosynthesis is a strategy for the treatment of these chronic diseases. METHODOLOGY/PRINCIPAL FINDINGS: Analogues of caffeic acid, including the naturally-occurring caffeic acid phenethyl ester (CAPE), were synthesized and evaluated for their capacity to inhibit 5-LO and LTs biosynthesis in human polymorphonuclear leukocytes (PMNL) and whole blood. Anti-free radical and anti-oxidant activities of the compounds were also measured. Caffeic acid did not inhibit 5-LO activity or LT biosynthesis at concentrations up to 10 µM. CAPE inhibited 5-LO activity (IC(50) 0.13 µM, 95% CI 0.08-0.23 µM) more effectively than the clinically-approved 5-LO inhibitor zileuton (IC(50) 3.5 µM, 95% CI 2.3-5.4 µM). CAPE was also more effective than zileuton for the inhibition of LT biosynthesis in PMNL but the compounds were equipotent in whole blood. The activity of the amide analogue of CAPE was similar to that of zileuton. Inhibition of LT biosynthesis by CAPE was the result of the inhibition of 5-LO and of AA release. Caffeic acid, CAPE and its amide analog were free radical scavengers and antioxidants with IC(50) values in the low µM range; however, the phenethyl moiety of CAPE was required for effective inhibition of 5-LO and LT biosynthesis. CONCLUSIONS: CAPE is a potent LT biosynthesis inhibitor that blocks 5-LO activity and AA release. The CAPE structure can be used as a framework for the rational design of stable and potent inhibitors of LT biosynthesis

CD14 Works with Toll-Like Receptor 2 to Contribute to Recognition and Control of Listeria monocytogenes Infection

Toll-like receptor 2 (TLR2) signaling has been shown to contribute to resistance to Listeria monocytogenes infection, as TLR2-deficient mice have a heightened susceptibility to infection with this organism. Because CD14 may associate with TLR2, we investigated the role of CD14 in Listeria responses. In both CD14-deficient and TLR2- deficient macrophages, nuclear factor κB translocation; CD40 and CD86; and the production of interleukin (IL)- 12, IL-6, tumor necrosis factor, and nitric oxide are reduced. The absence of CD14 augmented susceptibility to Listeria infection, reduced survival, and diminished bacterial clearance, as observed in TLR2-deficient mice.Compared with C57BL/6 control mice, CD14-deficient mice were observed to have a greater number of hepatic microabscesses containing abundant neutrophils, these abscesses were larger in size, and there was reduced inducible nitric oxide synthase expression. Further, mice that are both CD14 deficient and TLR2 deficient display susceptibility to infection that is comparable to that of mice deficient in either CD14 or TLR2 alone. Therefore, the present data demonstrate the role of CD14 and TLR2 in the recognition and control of Listeria infection and host resistanc

Combining SystemC, IP-XACT and UML/MARTE in model-based SoC design

International audienceModern SoC design may rely on models, or on highlevel description languages. Although very close, the benefits obtained from either sides can be substantially different (and mismatch may occur). The IP-Xact formalism, now a standard (IEEE 1685), was introduced to help assemble component IP from distinct sources into an integrated design. Components could be expressed in high-level HDLs such as SystemC, so should be the full design after translation. Experience shows that in fact this is hardly the case, specially in publicly available methods and tools. The present contribution goes one step into linking SystemC designs to their IP-Xact structural representation by translation. It then exports the resulting IP-Xact model into the UML/MARTE profile modeling framework, to allow to annotating existing models with additional information (again in a publicly available fashion, as opposed to vendor extensions). Even if our approach is still far from being complete, it bridges a number of gaps induce by the combined uses of SystemC and IP-Xact

Protein 4.1R expression in normal and dystrophic skeletal muscle

4.1R pre-mRNA alternative splicing results in multiple mRNA and protein isoforms that are expressed in virtually all tissues. More specifically, isoforms containing the alternative exon 17a, are exclusively expressed in muscle tissues. In this report, we show that these isoforms are preferentially present in the myoplasm of fast myofibres. 4.1R epitopes are also found at the sarcolemma of both slow and fast myofibres in normal muscle. Interestingly, they are absent from dystrophin-deficient sarcolemma of DMD muscle, and colocalize with partially expressed dystrophin in BMD muscle. We also show that alternative splicing of exons 16 and 17a is regulated during muscle differentiation in an asynchronous fashion, with an early inclusion of exon 16 in forming myotubes, and a late inclusion of exon 17a. Consistently, Western blot analysis led to characterize mainly an approximately 96/98-kDa doublet bearing exons 16-17a-encoding peptide, exclusively occurring in the differentiated muscle

Correction to: Intra‑articular injections of platelet‑rich plasma in symptomatic knee osteoarthritis: a consensus statement from French‑speaking experts.

peer reviewe

1H-NMR-Based Metabolomic Profiling of CSF in Early Amyotrophic Lateral Sclerosis

Background: Pathophysiological mechanisms involved in amyotrophic lateral sclerosis (ALS) are complex and none has identified reliable markers useful in routine patient evaluation. The aim of this study was to analyze the CSF of patients with ALS by 1 H NMR (Nuclear Magnetic Resonance) spectroscopy in order to identify biomarkers in the early stages of the disease, and to evaluate the biochemical factors involved in ALS. Methodology: CSF samples were collected from patients with ALS at the time of diagnosis and from patients without neurodegenerative diseases. One and two-dimensional 1 H NMR analyses were performed and metabolites were quantified by the ERETIC method. We compared the concentrations of CSF metabolites between both groups. Finally, we performed principal component (PCA) and discriminant analyses. Principal Findings: Fifty CSF samples from ALS patients and 44 from controls were analyzed. We quantified 17 metabolites including amino-acids, organic acids, and ketone bodies. Quantitative analysis revealed significantly lower acetate concentrations (p = 0.0002) in ALS patients compared to controls. Concentration of acetone trended higher (p = 0.015), and those of pyruvate (p = 0.002) and ascorbate (p = 0.003) were higher in the ALS group. PCA demonstrated that the pattern of analyzed metabolites discriminated between groups. Discriminant analysis using an algorithm of 17 metabolites reveale

Prions in Milk from Ewes Incubating Natural Scrapie

Since prion infectivity had never been reported in milk, dairy products originating from transmissible spongiform encephalopathy (TSE)-affected ruminant flocks currently enter unrestricted into the animal and human food chain. However, a recently published study brought the first evidence of the presence of prions in mammary secretions from scrapie-affected ewes. Here we report the detection of consistent levels of infectivity in colostrum and milk from sheep incubating natural scrapie, several months prior to clinical onset. Additionally, abnormal PrP was detected, by immunohistochemistry and PET blot, in lacteal ducts and mammary acini. This PrPSc accumulation was detected only in ewes harbouring mammary ectopic lymphoid follicles that developed consequent to Maedi lentivirus infection. However, bioassay revealed that prion infectivity was present in milk and colostrum, not only from ewes with such lympho-proliferative chronic mastitis, but also from those displaying lesion-free mammary glands. In milk and colostrum, infectivity could be recovered in the cellular, cream, and casein-whey fractions. In our samples, using a Tg 338 mouse model, the highest per ml infectious titre measured was found to be equivalent to that contained in 6 µg of a posterior brain stem from a terminally scrapie-affected ewe. These findings indicate that both colostrum and milk from small ruminants incubating TSE could contribute to the animal TSE transmission process, either directly or through the presence of milk-derived material in animal feedstuffs. It also raises some concern with regard to the risk to humans of TSE exposure associated with milk products from ovine and other TSE-susceptible dairy species