Understanding the Internet Pitchfork Mob: Internal Revolutionary Activity in Self-Regulated Online Communities

Research into organised online protest typically focuses on how digital activism empowers social movements. But what if an online community is rebelling against its platform owners? This study seeks to identify the trajectory of internally focused revolutionary activity in self-regulated online communities. Based on an analysis of three cases (Reddit, 2015; Mozilla, 2014, and Skyrim, 2015) it identifies six stages of revolution: incident, reaction, mobilization, action, negotiation, and a return to ‘normality’ with a new power equilibrium. For each stage, key events, relations between the community and platform managers, and the ways in which power is enacted through online means, are identified. This preliminary model for online community revolution offers potential for further work that has diagnostic, predictive and ameliorative value. Relations with online communities are of significant value in an era in which many platform-related business models are reliant on voluntary contributions of self-regulating online communities

Spectral-Spatial Classification of Hyperspectral Data based on a Stochastic Minimum Spanning Forest Approach

International audienceIn this paper, a new method for supervised hyperspectral data classification is proposed. In particular, the notion of stochastic Minimum Spanning Forest (MSF) is introduced. For a given hyperspectral image, a pixelwise classification is first performed. From this classification map, M marker maps are generated by randomly selecting pixels and labeling them as markers for the construction of Minimum Spanning Forests. The next step consists in building an MSF from each of the M marker maps. Finally, all the M realizations are aggregated with a maximum vote decision rule, in order to build the final classification map. The proposed method is tested on three different data sets of hyperspectral airborne images with different resolutions and contexts. The influence of the number of markers and of the number of realizations M on the results are investigated in experiments. The performance of the proposed method is compared to several classification techniques (both pixelwise and spectral-spatial) using standard quantitative criteria and visual qualitative evaluation

A Real-time Synthesizer of Naturalistic Congruent Audio-Haptic Textures

International audienceThis demo paper presents a multi-modal device able to generate real-time audio-haptic signal as response to the users' motion and produce naturalistic sensation. The device consists in a touch screen with haptic feedback based on ultrasonic friction modulation and a sound synthesizer. The device will help investigate audio-haptic interaction. In particular the system is built to allow for an exploration of di↵erent strategy of mapping audio and haptic signal to explore the limits of congruence. Such interactions could be the key to more informative and user-friendly touchscreens for Human-Machine-Interfaces

Propagation d’événements dans un graphe économique

International audienceThe diffusion models of infections in social networks are intensively studied these last years. The existing studies concern in particular disease and rumor diffusions in social networks or financial risk in banking networks. We propose in this paper to study the diffusion problem of events within social and economic networks. In particular, we define a new problem of diffusion called the Influence Classification Problem. The objective is to find the set of nodes which are impacted by a given network. We also propose two diffusion models based on a computed threshold according to the graph and event attributes. We test our models ontwo real and known events : the hurricane Katrina and the fusion of Bayer and MonsantoLes modèles de diffusion dans les réseaux sociaux sont beaucoup étudiés ces dernières années. Les études concernent notamment les diffusions de maladies et de rumeurs dans les réseaux sociaux ou de risques financiers dans les réseaux bancaires. Nous proposons dans cet article de répondre au problème de diffusion des événements au sein de réseaux économico-sociaux. En particulier, nous proposons d’étudier un nouveau problème de diffusion appelé Influence Classification Problem (ICP) dont l’objectif est de classifier automatiquement quels noeuds sont impactés pour un événement donné. Nous proposons également deux modèles de propagation basés sur un seuil calculé en fonction desattributs du graphe et de l’événement. Nous testons nos modèles sur deux événements connus : l’ouragan Katrina et l’acquisition de Monsanto par Bayer

Violence sexuelle en période de guerre: une revue des études empiriques

Cet article passe en revue l’état des connaissances sur la violence sexuelle en période de conflit armé, ainsi que les différentes méthodologies utilisées. Il examine la littérature théorique et empirique, en utilisant une combinaison de méthodes qualitatives et quantitatives. Les résultats montrent que la violence sexuelleﾠ«structurelle » a ses racines dans diverses institutions sociales qui l’exacerbent en la transformant en violence «conjoncturelle » et qui font obstacle à la prévention et la protection des victimes. La violence sexuelle a des conséquences physiques, psychologiques et sociales graves et peut replonger les victimes dans un cycle de violence. Nos travaux suggèrent que la violence sexuelle devra être analysée en période de conflit aussi bien qu’en période de paix d’où elle tire ses origines. Les analyses devraient couvrir les perspectives des auteurs de violence aussi bien que des victimes, indépendamment de leur sexe

Inactivating the lipid kinase activity of PI3KC2β is sufficient to rescue myotubular myopathy in mice

Phosphoinositides (PI) are membrane lipids that regulate signal transduction and vesicular trafficking. X-linked centronuclear myopathy (XLCNM), also called myotubular myopathy, results from loss-of-function mutations in the Mtm1 gene, which encodes the myotubularin phosphatidylinositol 3-phosphate (PtdIns3P) lipid phosphatase. No therapy for this disease is currently available. Previous studies showed that loss of expression of the class II phosphoinositide 3-kinase (PI3K) PI3K-C2β protein improved the phenotypes of a XLCNM mouse model. PI3Ks are well known to have extensive scaffolding functions and the importance of the catalytic activity of this PI3K for rescue remains unclear. Here, using PI3K-C2β kinase-dead mice, we show that the selective inactivation of PI3K-C2β kinase activity is sufficient to fully prevent muscle atrophy and weakness, histopathology, and sarcomere and triad disorganization in Mtm1 knockout mice. This rescue correlates with normalization of PtdIns3P level and mTORC1 activity, a key regulator of protein synthesis and autophagy. Conversely, lack of PI3K-C2β kinase activity did not rescue the histopathology of the BIN1 autosomal centronuclear myopathy mouse model. Overall, these findings support the development of specific PI3K-C2β kinase inhibitors to cure myotubular myopathy

Determining areas that require indoor insecticide spraying using Multi Criteria Evaluation, a decision-support tool for malaria vector control programmes in the Central Highlands of Madagascar

BACKGROUND: The highlands of Madagascar present an unstable transmission pattern of malaria. The population has no immunity, and the central highlands have been the sites of epidemics with particularly high fatality. The most recent epidemic occurred in the 1980s, and caused about 30,000 deaths. The fight against malaria epidemics in the highlands has been based on indoor insecticide spraying to control malaria vectors. Any preventive programme involving generalised cover in the highlands will require very substantial logistical support. We used multicriteria evaluation, by the method of weighted linear combination, as basis for improved targeting of actions by determining priority zones for intervention. RESULTS: Image analysis and field validation showed the accuracy of mapping rice fields to be between 82.3% and 100%, and the Kappa coefficient was 0.86 to 0.99. A significant positive correlation was observed between the abundance of the vector Anopheles funestus and temperature; the correlation coefficient was 0.599 (p < 0.001). A significant negative correlation was observed between vector abundance and human population density: the correlation coefficient was -0.551 (p < 0.003). Factor weights were determined by pair-wise comparison and the consistency ratio was 0.04. Risk maps of the six study zones were obtained according to a gradient of risk. Nine of thirteen results of alert confirmed by the Epidemiological Surveillance Post were in concordance with the risk map. CONCLUSION: This study is particularly valuable for the management of vector control programmes, and particularly the reduction of the vector population with a view to preventing disease. The risk map obtained can be used to identify priority zones for the management of resources, and also help avoid systematic and generalised spraying throughout the highlands: such spraying is particularly difficult and expensive. The accuracy of the mapping, both as concerns time and space, is dependent on the availability of data. Continuous monitoring of malaria transmission factors must be undertaken to detect any changes. A regular case notification allows risk map to be verified. These actions should therefore be implemented so that risk maps can be satisfactorily assessed

Post-Paleozoic evolution of the northern Ardenne Massif constrained by apatite fission-track thermochronology and geological data

International audienceThe exhumation history of basement areas is poorly constrained because of large gaps in thesedimentary record. Indirect methods including low temperature thermochronology may be used to estimateexhumation but these require an inverse modeling procedure to interpret the data. Solutions from suchmodeling are not always satisfactory as they may be too broad or may conflict with independent geologicaldata. This study shows that the input of geological constraints is necessary to obtain a valuable and refinedexhumation history and to identify the presence of a former sedimentary cover presently completely eroded.Apatite fission-track (AFT) data have been acquired on the northern part of the Ardenne Massif close to theVariscan front and in the southern Brabant, in particular for the Visean ash-beds. Apatite fission-track agesfor surface samples range between 140 ± 13 and 261 ± 33Ma and confined tracks lengths are rangingbetween 12.6 ± 0.2 and 13.8 ± 0.2 mm. Thermal inversion has been realized assuming that (1) samples wereclose to the surface (20–40 °C) during Triassic times, this is supported by remnants of detrital UpperPermian–Triassic sediments preserved in the south of the Ardenne and in the east (border of the Roer Grabenand Malmédy Graben), and (2) terrestrial conditions prevailed during the Early Cretaceous for the ArdenneMassif, as indicated by radiometric ages on paleoweathering products. Inversion of the AFT datacharacterizes higher temperatures than surface temperatures during most of the Jurassic. Temperature rangeis wide but is compatible with the deposition on the northern Ardenne of a significant sedimentary cover,which has been later eroded during the Late Jurassic and/or the Early Cretaceous. Despite the presence ofsmall outliers of Late Cretaceous (Hautes Fagnes area), no evidence is recorded by the fission-track data forthe deposition of a significant chalk cover as highlighted in different parts of western Europe. These resultsquestion the existence of the London-Brabant Massif as a permanent positive structure during the Mesozoic.L’évaluation des épaisseurs érodées sur les socles n’est pas immédiate car l’absence fréquente de couverture sédimentaire rend muette leur quantification sur une grande période de temps. Des méthodes indirectes comme la thermochronologie basse température permettent d’appréhender l’érosion à condition d’inverser correctement les données par modélisation. Les résultats de l’inversion ne sont pas toujours en accord avec les données géologiques ou sont trop imprécis pour être pertinents. Cette étude montre que la prise en compte de contraintes géologiques est nécessaire pour obtenir une histoire cohérente, définir l’ampleur de l’érosion et identifier la présence d’une couverture sédimentaire aujourd’hui érodée. Des données traces de fission dans les cristaux d’apatite ont été réalisées dans le nord du massif de l’Ardenne à proximité du front varisque et au sud du Massif du Brabant, en particulier sur des échantillons de cinérites viséennes. Les âges traces de fission des échantillons prélevés à la surface varient entre 140 ± 13 et 261 ± 33 Ma et la longueur des traces confinées horizontales est comprise entre 12,6 ± 0,2 et 13,8 ± 0,2 μm. L’inversion thermique de ces données a été réalisée en prenant comme hypothèses : (1) la proximité des échantillons de la surface (20–40 °C) au cours du Trias, hypothèse étayée par des témoins de couverture du Permien supérieur et du Trias au sud et à l’est du massif de l’Ardenne (grabens de la Roer et de Malmédy) ; (2) l’existence de conditions continentales au cours du Crétacé inférieur, en accord avec des âges de cette période pour des profils d’altération datés localisés dans le massif de l’Ardenne. Le résultat de cette inversion suggère des températures assez élevées au cours du Jurassique. Ces températures sont interprétées comme le résultat du dépôt d’une couverture sédimentaire qui a ensuite été érodée au Jurassique supérieur et/ou au Crétacé inférieur. Malgré la présence de quelques témoins du Crétacé supérieur (notamment dans les Hautes Fagnes), les données ne permettent pas de détecter le dépôt d’une série épaisse datée du Crétacé supérieur comme c’est le cas dans plusieurs régions d’Europe de l’Ouest. Ces résultats remettent en question l’existence de la structure positive du massif de Londres-Brabant au cours du Jurassique en identifiant des mouvements verticaux significatifs

Positive and negative affect is related to experiencing chest pain during exercise-induced myocardial ischemia

© 2017 by the American Psychosomatic Society. Objective: Silent myocardial ischemia is thought to be associated with worse cardiovascular outcomes due to a lack of perception of pain cues that initiate treatment seeking. Negative affect (NA) has been associated with increased pain reporting and positive affect (PA) with decreased pain reporting, but these psychological factors have not been examined within the context of myocardial ischemia. This study evaluated the associations between PA, NA, and chest pain reporting in patients with and without ischemia during exercise testing. Methods: A total of 246 patients referred for myocardial perfusion single-photon emission computed tomography exercise stress testing completed the positive and negative affect schedule-expanded version, a measure of PA and NA. Presence of chest pain and myocardial ischemia were evaluated using standardized protocols. Results: Logistic regression analyses revealed that for every 1-point increase in NA, there was a 13% higher chance for ischemic patients (odds ratio [OR] = 1.13; 95 % confidence interval [CI] = 1.02 to 1.26) and an 11% higher chance in nonischemic patients (OR = 1.11; 95% CI = 1.03 to 1.19) to report chest pain. A significant interaction of PA and NA on chest pain reporting (ß = 0.02; 95% CI = 0.002 to 0.031) was also observed; nonischemic patients with high NA and PA reported more chest pain (57%) versus patients with low NA and low PA (13%), with high NA and low PA (17%), and with high PA and low NA (7%). Conclusions: Patients who experience higher NA are more likely to report experiencing chest pain. In patients without ischemia, high NA and PA was also associated with a higher likelihood of reporting chest pain. Results suggest that high levels of PA as well as NA may increase the experience and/or reporting of chest pain

Longitudinal survey of malaria morbidity over 10 years in Saharevo (Madagascar): further lessons for strengthening malaria control

<p>Abstract</p> <p>Background</p> <p>Madagascar has been known for having bio-geo-ecological diversity which is reflected by a complex malaria epidemiology ranging from hyperendemic to malaria-free areas. Malaria-related attacks and infection are frequently recorded both in children and adults living in areas of low malaria transmission. To integrate this variability in the national malaria control policy, extensive epidemiological studies are required to up-date previous records and adjust strategies.</p> <p>Methods</p> <p>A longitudinal malaria survey was conducted from July 1996 to June 2005 among an average cohort of 214 villagers in Saharevo, located at 900 m above the sea. Saharevo is a typical eastern foothill site at the junction between a costal wet tropical area (equatorial malaria pattern) and a drier high-altitude area (low malaria transmission).</p> <p>Results</p> <p>Passive and active malaria detection revealed that malaria transmission in Saharevo follows an abrupt seasonal variation. Interestingly, malaria was confirmed in 45% (1,271/2,794) of malaria-presumed fevers seen at the health centre. All four <it>Plasmodia </it>that infect humans were also found: <it>Plasmodium falciparum</it>; <it>Plasmodium vivax</it>, <it>Plasmodium malariae </it>and <it>Plasmodium ovale</it>. Half of the malaria-presumed fevers could be confirmed over the season with the highest malaria transmission level, although less than a quarter in lower transmission time, highlighting the importance of diagnosis prior to treatment intake. <it>P. falciparum </it>malaria has been predominant (98%). The high prevalence of <it>P. falciparum </it>malaria affects more particularly under 10 years old children in both symptomatic and asymptomatic contexts. Children between two and four years of age experienced an average of 2.6 malaria attacks with <it>P. falciparum </it>per annum. Moreover, estimated incidence of <it>P. falciparum </it>malaria tends to show that half of the attacks (15 attacks) risk to occur during the first 10 years of life for a 60-year-old adult who would have experienced 32 malaria attacks.</p> <p>Conclusion</p> <p>The incidence of malaria decreased slightly with age but remained important among children and adults in Saharevo. These results support that a premunition against malaria is slowly acquired until adolescence. However, this claims for a weak premunition among villagers in Saharevo and by extension in the whole eastern foothill area of Madagascar. While the Malagasy government turns towards malaria elimination plans nowadays, choices and expectations to up-date and adapt malaria control strategies in the foothill areas are discussed in this paper.</p