7,037 research outputs found

    Learning 3D Navigation Protocols on Touch Interfaces with Cooperative Multi-Agent Reinforcement Learning

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    Using touch devices to navigate in virtual 3D environments such as computer assisted design (CAD) models or geographical information systems (GIS) is inherently difficult for humans, as the 3D operations have to be performed by the user on a 2D touch surface. This ill-posed problem is classically solved with a fixed and handcrafted interaction protocol, which must be learned by the user. We propose to automatically learn a new interaction protocol allowing to map a 2D user input to 3D actions in virtual environments using reinforcement learning (RL). A fundamental problem of RL methods is the vast amount of interactions often required, which are difficult to come by when humans are involved. To overcome this limitation, we make use of two collaborative agents. The first agent models the human by learning to perform the 2D finger trajectories. The second agent acts as the interaction protocol, interpreting and translating to 3D operations the 2D finger trajectories from the first agent. We restrict the learned 2D trajectories to be similar to a training set of collected human gestures by first performing state representation learning, prior to reinforcement learning. This state representation learning is addressed by projecting the gestures into a latent space learned by a variational auto encoder (VAE).Comment: 17 pages, 8 figures. Accepted at The European Conference on Machine Learning and Principles and Practice of Knowledge Discovery in Databases 2019 (ECMLPKDD 2019

    Effect of Curcuma zedoaria crude extract against tumor progression and immunomodulation

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    The aim of the present work was to study the effect of the crude extract of Curcuma zedoaria on peripheral blood cells and tumor progression in C57Bl/6J mice injected with B16F10 murine melanoma cells. The intraperitoneal therapy showed a significant increase in total white and red blood cell counts, a decrease in peritoneal cell number and tumor volume reduction, whereas the oral administration revealed a noteworthy augmentation only in total leukocyte count. These results contribute to evaluate the importance of alternative treatments that employ phytotherapic compounds against tumor progression and its possible immunomodulation

    PMH23 DEVELOPMENT AND ASSESSMENT OF HEALTH STATE UTILITIES FOR ATTENTION DEFICIT/HYPERACTIVITY DISORDER IN CHILDREN USING PARENT PROXY REPORT

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    SHRUB AND TREE SPECIES COMPOSITION IN THE CERRADOS OF SOUTHWEST MINAS GERAIS

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    In order to improve the knowledge about variations in the floristic community of Brazilian cerrado, especially in regard to soil and climate conditions, we conducted a floristic assessment of the tree and shrub community of three disjoint adjacent regions situated in three municipalities of southwest Minas Gerais state (geographical coordinates 20-23 degrees S and 44-47 degrees W). Over a period of 24 months, in 49 allocated plots of 20 x 20 m, all tree and shrub species 1 m high or more in vegetative and/or reproductive stage were sampled. Additional random samples of blossoming plants were collected outside plots, and each plot was analyzed and categorized for soil type. 170 botanical species were identified belonging to 103 genera and 46 families. Family Fabaceae and genus Miconia presented the largest number of species. Although the cerrado of southwest Minas Gerais extends over marginal areas of occurrence of Brazilian cerrado, its floristic composition is rich not only in species but also in genera and families. Some species found in these cerrados also occur in local semideciduous forests, while other species that are frequently found in other areas of cerrado were not found in southwest Minas Gerais. Tibouchina sellowiana does not feature in the list of species occurring in Brazilian cerrados. There is little similarity among the three sampled areas due to soil factors and different types of human influence in each of the areas. Alpinopolis presented cerrado sensu stricto - subtype cerrado ralo, with 75 species and red-yellow latosol. Campo do Meio presented cerrado sensu stricto - subtype cerrado tipico, with 88 species and red latosol. Pimenta falls under the cerraddo category, with 124 species and red latosol. On the subsurface, the soil of Pimenta was found to present lower Al(+++)saturation, which apparently shapes conditions for a more vigorous vegetation. The cerrado soils sampled in this study showed high similarity to cerrado soils in other parts of Brazil.15214215

    Comparison of clinical burden between patients with erosive hand osteoarthritis and inflammatory arthritis in symptomatic community-dwelling adults: the Keele clinical assessment studies.

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    OBJECTIVE: To investigate in the general population the clinical impact of erosive OA in interphalangeal joints (IPJs) compared with symptomatic radiographic hand OA and inflammatory arthritis. METHODS: Standardized assessments with hand radiographs were performed in participants of two population-based cohorts in North Staffordshire with hand symptoms lasting ≥1 day in the past month. Erosive OA was defined as the presence of an eroded or remodelled phase in ≥1 IPJ using the Verbruggen-Veys method. Radiographic hand OA was defined as the presence of ≥1 IPJ/first carpometacarpal joint with a Kellgren-Lawrence score of ≥2. Diagnoses of inflammatory arthritis were based on medical records. Hand pain and disability were assessed with the Australian/Canadian Hand Osteoarthritis Index (AUSCAN). Linear regression analyses were used to compare clinical determinants between groups and calculate mean differences with 95% CIs, adjusted for age and sex. RESULTS: Of 1076 participants with hand symptoms [60% women, mean age 64.8 years (s.d. 8.3 years)]; 80 persons (7.4%) had erosive OA. The population prevalence of erosive OA in ≥1 IPJ was 2.4% (95% CI 1.8, 3.0). Persons with erosive OA reported more pain and disability than persons with symptomatic radiographic hand OA [adjusted mean difference 1.3 (95% CI 0.3, 2.3) and 2.3 (95% CI 0.4, 4.2), respectively]. Individuals with inflammatory arthritis (n = 44) reported more pain and disability than those with erosive OA [adjusted mean difference 1.7 (95% CI 0.05, 3.4) and 6.3 (95% CI 2.8, 9.9), respectively]. CONCLUSION: While erosive OA has a greater impact than symptomatic radiographic hand OA in the general population, it is not as severe in terms of hand pain and disability as inflammatory RA

    Online Groups in Educational Settings: An Opportunity for Argumentation

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    The aim of this paper is to explore how students and teachers used posts in five groups on Facebook and how argumentation emerged as a communicative activity. For understanding such argumentative process, this study is framed in the Cultural Historical Activity Theory (CHAT), with a methodological perspective that enables the participants to act as co-authors of the intervention design. We draw our data from the posts inside five groups of teacher-students on Facebook, from February/2013 to June/2014, which were analysed qualitatively, considering discursive and linguistic aspects of the posts. Our findings pointed out that in situation in which collaboration occurred among students, there was a transition from authoritative discourse to internally persuasive discourse in the posts with argumentative indicators

    Multiwavelength Observations of Pulsar Wind Nebulae

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    The extended nebulae formed as pulsar winds expand into their surroundings provide information about the composition of the winds, the injection history from the host pulsar, and the material into which the nebulae are expanding. Observations from across the electromagnetic spectrum provide constraints on the evolution of the nebulae, the density and composition of the surrounding ejecta, the geometry of the central engines, and the long-term fate of the energetic particles produced in these systems. Such observations reveal the presence of jets and wind termination shocks, time-varying compact emission structures, shocked supernova ejecta, and newly formed dust. Here I provide a broad overview of the structure of pulsar wind nebulae, with specific examples from observations extending from the radio band to very-high-energy gamma-rays that demonstrate our ability to constrain the history and ultimate fate of the energy released in the spin-down of young pulsars.Comment: 20 pages, 11 figures. Invited review to appear in Proc. of the inaugural ICREA Workshop on "The High-Energy Emission from Pulsars and their Systems" (2010), eds. N. Rea and D. Torres, (Springer Astrophysics and Space Science series

    Household Transmission of Rotavirus in a Community with Rotavirus Vaccination in Quininde, Ecuador

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    Background: We studied the transmission of rotavirus infection in households in peri-urban Ecuador in the vaccination era. Methods: Stool samples were collected from household contacts of child rotavirus cases, diarrhea controls and healthy controls following presentation of the index child to health facilities. Rotavirus infection status of contacts was determined by RT-qPCR. We examined factors associated with transmissibility (index-case characteristics) and susceptibility (householdcontact characteristics). Results: Amongst cases, diarrhea controls and healthy control household contacts, infection attack rates (iAR) were 55%, 8% and 2%, (n = 137, 130, 137) respectively. iARs were higher from index cases with vomiting, and amongst siblings. Disease ARs were higher when the index child was ,18 months and had vomiting, with household contact ,10 years and those sharing a room with the index case being more susceptible. We found no evidence of asymptomatic infections leading to disease transmission. Conclusion: Transmission rates of rotavirus are high in households with an infected child, while background infections are rare. We have identified factors associated with transmission (vomiting/young age of index case) and susceptibility (young age/sharing a room/being a sibling of the index case). Vaccination may lead to indirect benefits by averting episodes or reducing symptoms in vaccinees
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