Génération automatique de mélodie par la programmation par contraintes

La programmation par contraintes est un type de programmation déclarative, un paradigme naturellement adapté au traitement de problèmes musicaux. En effet, la composition musicale s’apparente à un processus déclaratif pendant lequel le compositeur travaille pour créer de la musique qui respecte les règles générales de l’art et les critères plus spécifiques du style adopté tout en y incorporant ses propres contraintes. Le parallèle entre cet exercice et la résolution d’un problème de satisfaction de contraintes se fait donc instinctivement. La principale difficulté se trouve au niveau de la modélisation du problème. Une pièce musicale est composée de plusieurs dimensions entre lesquelles existent beaucoup d’interactions. Il est pratiquement impossible pour un système informatique de représenter précisément toutes ces dépendances. Les systèmes de contraintes conçus pour traiter de problèmes musicaux se concentrent alors sur des dimensions en particulier. Parmi ces problèmes, on retrouve la génération de mélodie qui concerne donc les hauteurs et les durées des notes d’une ligne mélodique accompagnée par une suite d’accords. La modélisation d’un tel problème se concentre sur une séquence de notes et ne présente donc aucun élément de polyphonie ou d’instrumentation par exemple, ce qui simplifie la situation. L’objectif de ce projet est de concevoir un système de génération automatique de mélodie selon une suite d’accords donnée qui utilise les informations d’un corpus pour guider la composition. Deux des principaux défis de ce type de problème sont l’organisation des variables et le contrôle de la structure globale de la mélodie générée. Pour relever le premier, nous avons émis l’hypothèse qu’un système structuré hiérarchiquement offrait le plus de flexibilité et permettrait donc d’exprimer les contraintes plus facilement. En ce qui concerne la structure du résultat, nous avons mis au point un algorithme de détection de patrons répétitifs basé sur des arbres des suffixes qui permet au système de répliquer les éléments de la structure d’une mélodie existante.----------ABSTRACT: Constraint programming belongs to the declarative programming paradigm which is naturally suited to tackle musical problems. Musical composition can be seen as a declarative process during which the composer works to create music respecting the general and specific rules of the chosen style and also adds his own touch. The connection between this process and resolving a constraint satisfaction problem is made instinctively. The main challenge of this field is modeling the problem because of all the different dimensions which interact together in a music piece. It is virtually impossible for a computer-based system to provide a view of the same quality a human composer would have. Thus, constraint systems designed to tackle musical problems usually focus on specific dimensions. One of these problems consists of generating a melody given a chord sequence, which only involves note durations and pitches, there is no concept of polyphony or instrumentation, for example. The goal of this project is to design and implement a system able to generate a melody given a chord sequence, using information from a corpus to guide composition. Two of the main challenges of this kind of problems are the variables arrangement and the control of the global structure of the melody. Regarding variables, we made the assumption that a hierarchical organization would improve the system’s flexibility which would make it easier to express constraints. For the structure, we designed an algorithm which uses suffix trees to detect repeating patterns in existing melodies and made the system able to replicate them in the result. Our system is made of hierarchically organized blocs. The melody is made of bars which contain chords under which are located the notes. Each block has a variable number of notes which needs to be fixed first in order to instantiate the corresponding variables. This means that the system has to work in two phases. The first one assigns a rhythm pattern to every bar, which decides both the number of notes and their durations. The second phase fixes the pitch of every note of the melody

Considerations in the Use of Podcasts for Teaching and Learning in Occupational Therapy: A Scoping Study

Evidence-based practice integrates and supports the best interventions in clinical practice. However, a gap of about ten years may elapse between the production of evidence and integration of best practices in clinical settings. Some technologies, such as podcasting, have become increasingly popular and are emerging as an innovative teaching modality that can support knowledge acquisition and integration. This scoping study gathered and synthesized the information in the literature regarding the use of podcasts by occupational therapy clinicians and students as a means for teaching and learning evidence-based knowledge. A scoping study approach was used following the five stages defined by Arksey and O\u27Malley. In four databases and using 40 keywords, two team members selected and cross-checked articles. Two team members also extracted data and analyzed them in the form of descriptive statistics and salience (recurrence and importance). Of the 46 articles selected, seven broad categories of 20 important themes related to the use of podcasting were identified: facilitators and obstacles to podcast use, advantages and disadvantages of podcasts, effects of podcasts, potential utility of podcasts, and elements to consider for podcast creation. Podcasting is an innovative and appropriate modality for the retention of knowledge and the optimization of practical skills. It differs from traditional methods in its ease of access and portability. Many positive effects have been associated with its use. However, podcasts should not replace class attendance or other active learning opportunities

Flexible 1kV thin-film transistor driving out-of-plane dielectric elastomer actuator

This work demonstrates dielectric elastomer actuators controlled by the world's first thin-film transistors on flexible substrate operating at 1kV, thereby enabling locally switching high-voltages on DEAs using a low control voltage. The high voltages required to drive DEAs limit their integration in complex systems, such as high resolution haptic displays and multiple-degree-of-freedom robotics. We report here a top-gate, thin-film transistor (TFT) with coplanar electrodes specifically designed to drive DEAs. The TFTs are fabricated on flexible polyimide, using solution-processed zinc-tin oxide, offset gate and thick dielectric bilayer of Alumina and Parylene. The TFT switches reliably at up to 1kV, outperforming on this metric all published high-voltage TFTs. The on-off current ratio ranges from 20 to 200, the saturation mobility is 0.1cm2/Vs, and the threshold voltage is 10V. Our DEAs are designed for maximal actuation strain at 1kV, to match the maximal voltage of the TFTs. The DEA is a diaphragm actuator: a suspended non-prestretched membrane with electrodes on both sides. The circular electrode has a 5 mm diameter and the silicone membrane is 17um thick. A backpressure of 50mbar is applied to the membrane. The TFT is wired in parallel with the DEA. A change of out-of-plane displacement of 350um is achieved with 30V applied to the gate, for a circuit bias voltage of 1.4kV. The TFT + DEA operate reliably for several weeks

Flexible Zinc-Tin Oxide Thin Film Transistors Operating at 1 kV for Integrated Switching of Dielectric Elastomer Actuators Arrays

Flexible high-voltage thin- lm transistors (HVTFTs) operating at more than 1 kV are integrated with compliant dielectric elastomer actuators (DEA) to create a exible array of 16 independent actuators. To allow for high-voltage operation, the HVTFT implements a zinc–tin oxide channel, a thick dielectric stack, and an offset gate. At a source–drain bias of 1 kV, the HVTFT has a 20 μA on-current at a gate voltage bias of 30 V. Their electrical characteris- tics enable the switching of DEAs which require drive voltages of over 1 kV, making control of an array simpler in comparison to the use of external high-voltage switching. These HVTFTs are integrated in a flexible haptic display consisting of a 4 × 4 matrix of DEAs and HVTFTs. Using a single 1.4 kV supply, each DEA is independently switched by its associated HVTFT, requiring only a 30 V gate voltage for full DEA de ection. The 4 × 4 display operates well even when bent to a 5 mm radius of curvature. By enabling DEA switching at low voltages, flexible metal-oxide HVTFTs enable complex flexible systems with dozens to hundreds of independent DEAs for applications in haptics, Braille displays, and soft robotics

Framework for managing the COVID-19 infodemic : Methods and results of an online, crowdsourced WHO technical consultation

Background: An infodemic is an overabundance of information—some accurate and some not—that occurs during an epidemic. In a similar manner to an epidemic, it spreads between humans via digital and physical information systems. It makes it hard for people to find trustworthy sources and reliable guidance when they need it. Objective: A World Health Organization (WHO) technical consultation on responding to the infodemic related to the coronavirus disease (COVID-19) pandemic was held, entirely online, to crowdsource suggested actions for a framework for infodemic management. Methods: A group of policy makers, public health professionals, researchers, students, and other concerned stakeholders was joined by representatives of the media, social media platforms, various private sector organizations, and civil society to suggest and discuss actions for all parts of society, and multiple related professional and scientific disciplines, methods, and technologies. A total of 594 ideas for actions were crowdsourced online during the discussions and consolidated into suggestions for an infodemic management framework. Results: The analysis team distilled the suggestions into a set of 50 proposed actions for a framework for managing infodemics in health emergencies. The consultation revealed six policy implications to consider. First, interventions and messages must be based on science and evidence, and must reach citizens and enable them to make informed decisions on how to protect themselves and their communities in a health emergency. Second, knowledge should be translated into actionable behavior-change messages, presented in ways that are understood by and accessible to all individuals in all parts of all societies. Third, governments should reach out to key communities to ensure their concerns and information needs are understood, tailoring advice and messages to address the audiences they represent. Fourth, to strengthen the analysis and amplification of information impact, strategic partnerships should be formed across all sectors, including but not limited to the social media and technology sectors, academia, and civil society. Fifth, health authorities should ensure that these actions are informed by reliable information that helps them understand the circulating narratives and changes in the flow of information, questions, and misinformation in communities. Sixth, following experiences to date in responding to the COVID-19 infodemic and the lessons from other disease outbreaks, infodemic management approaches should be further developed to support preparedness and response, and to inform risk mitigation, and be enhanced through data science and sociobehavioral and other research. Conclusions: The first version of this framework proposes five action areas in which WHO Member States and actors within society can apply, according to their mandate, an infodemic management approach adapted to national contexts and practices. Responses to the COVID-19 pandemic and the related infodemic require swift, regular, systematic, and coordinated action from multiple sectors of society and government. It remains crucial that we promote trusted information and fight misinformation, thereby helping save lives.peer-reviewe

Genome Evolution of Two Genetically Homogeneous Infectious Bursal Disease Virus Strains During Passages in vitro and ex vivo in the Presence of a Mutagenic Nucleoside Analog

The avibirnavirus infectious bursal disease virus (IBDV) is responsible for a highly contagious and sometimes lethal disease of chickens (Gallus gallus). IBDV genetic variation is well-described for both field and live-attenuated vaccine strains, however, the dynamics and selection pressures behind this genetic evolution remain poorly documented. Here, genetically homogeneous virus stocks were generated using reverse genetics for a very virulent strain, rvv, and a vaccine-related strain, rCu-1. These viruses were serially passaged at controlled multiplicities of infection in several biological systems, including primary chickens B cells, the main cell type targeted by IBDV in vivo. Passages were also performed in the absence or presence of a strong selective pressure using the antiviral nucleoside analog 7-deaza-2′-C-methyladenosine (7DMA). Next Generation Sequencing (NGS) of viral genomes after the last passage in each biological system revealed that (i) a higher viral diversity was generated in segment A than in segment B, regardless 7DMA treatment and viral strain, (ii) diversity in segment B was increased by 7DMA treatment in both viruses, (iii) passaging of IBDV in primary chicken B cells, regardless of 7DMA treatment, did not select cell-culture adapted variants of rvv, preserving its capsid protein (VP2) properties, (iv) mutations in coding and non-coding regions of rCu-1 segment A could potentially associate to higher viral fitness, and (v) a specific selection, upon 7DMA addition, of a Thr329Ala substitution occurred in the viral polymerase VP1. The latter change, together with Ala270Thr change in VP2, proved to be associated with viral attenuation in vivo. These results identify genome sequences that are important for IBDV evolution in response to selection pressures. Such information will help tailor better strategies for controlling IBDV infection in chickens

Genomic and biological characterization of chiltepin yellow mosaic virus, a new tymovirus infecting Capsicum annuum var. aviculare in Mexico.

The characterization of viruses infecting wild plants is a key step towards understanding the ecology of plant viruses. In this work, the complete genomic nucleotide sequence of a new tymovirus species infecting chiltepin, the wild ancestor of Capsicum annuum pepper crops, in Mexico was determined, and its host range has been explored. The genome of 6,517 nucleotides has the three open reading frames described for tymoviruses, putatively encoding an RNA-dependent RNA polymerase, a movement protein and a coat protein. The 5′ and 3′ untranslated regions have structures with typical signatures of the tymoviruses. Phylogenetic analyses revealed that this new virus is closely related to the other tymoviruses isolated from solanaceous plants. Its host range is mainly limited to solanaceous species, which notably include cultivated Capsicum species. In the latter, infection resulted in a severe reduction of growth, indicating the potential of this virus to be a significant crop pathogen. The name of chiltepin yellow mosaic virus (ChiYMV) is proposed for this new tymovirus

BMJ Open

Introduction Neonatal sepsis outreaches all causes of neonatal mortality worldwide and remains a major societal burden in low and middle income countries. In addition to limited resources, endemic morbidities, such as malaria and prematurity, predispose neonates and infants to invasive infection by altering neonatal immune response to pathogens. Nevertheless, thoughtful epidemiological, diagnostic and immunological evaluation of neonatal sepsis and the impact of gestational malaria have never been performed. Methods and analysis A prospective longitudinal multicentre follow-up of 580 infants from birth to 3 months of age in urban and suburban Benin will be performed. At delivery, and every other week, all children will be examined and clinically evaluated for occurrence of sepsis. At delivery, cord blood systematic analysis of selected plasma and transcriptomic biomarkers (procalcitonin, interleukin (IL)-6, IL-10, IP10, CD74 and CX3CR1) associated with sepsis pathophysiology will be evaluated in all live births as well as during the follow-up, and when sepsis will be suspected. In addition, whole blood response to selected innate stimuli and extensive peripheral blood mononuclear cells phenotypic characterisation will be performed. Reference intervals specific to sub-Saharan neonates will be determined from this cohort and biomarkers performances for neonatal sepsis diagnosis and prognosis tested. Ethics and dissemination Ethical approval has been obtained from the Comité d’Ethique de la Recherche – Institut des Sciences Biomédicales Appliquées (CER-ISBA 85 - 5 April 2016, extended on 3 February 2017). Results will be disseminated through international presentations at scientific meetings and publications in peer-reviewed journals

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data