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Parcellation-based connectome assessment by using structural and functional connectivity
No full textConnectome analysis of the human brain structural and functional architecture provides a unique opportunity to understand the organization of brain networks. In this work, we investigate a novel large scale parcellation-based connectome, merging together information coming from resting state fMRI (rs-fMRI) data and diffusion tensor imaging (DTI) measurements
An interactive tool for semi-automated leaf annotation
No full textHigh throughput plant phenotyping is emerging as a necessary step towards meeting agricultural demands of the future. Central to its success is the development of robust computer vision algorithms that analyze images and extract phenotyping information to be associated with genotypes and environmental conditions for identifying traits suitable for further development. Obtaining leaf level quantitative data is important towards understanding better this interaction. While certain efforts have been made to obtain such information in an automated fashion, further innovations are necessary. In this paper we present an annotation tool that can be used to semi-automatically segment leaves in images of rosette plants. This tool, which is designed to exist in a stand-alone fashion but also in cloud based environments, can be used to annotate data directly for the study of plant and leaf growth or to provide annotated datasets for learning-based approaches to extracting phenotypes from images. It relies on an interactive graph-based segmentation algorithm to propagate expert provided priors (in the form of pixels) to the rest of the image, using the random walk formulation to find a good per-leaf segmentation. To evaluate the tool we use standardized datasets available from the LSC and LCC 2015 challenges, achieving an average leaf segmentation accuracy of almost 97% using scribbles as annotations. The tool and source code are publicly available at http://www.phenotiki.com and as a GitHub repository at https://github.com/phenotiki/LeafAnnotationTool
Static VS Dynamic Reversibility in CCS
No full textThe notion of reversible computing is attracting interest because of its applications in diverse fields, in particular the study of programming abstractions for fault tolerant systems. Reversible CCS (RCCS), proposed by Danos and Krivine, enacts reversibility by means of memory stacks. Ulidowski and Phillips proposed a general method to reverse a process calculus given in a particular SOS format, by exploiting the idea of making all the operators of a calculus static. CCSK is then derived from CCS with this method. In this paper we show that RCCS is at least as expressive as CCSK
(edited by) Proceedings 9th Interaction and Concurrency Experience, ICE 2016, Heraklion, Greece, 8-9 June 2016
No full textThis volume contains the proceedings of ICE 2016, the 9th Interaction and Concurrency Experience, which was held in Heraklion, Greece on the 8th and 9th of June 2016 as a satellite event of DisCoTec 2016. The ICE procedure for paper selection allows PC members to interact, anonymously, with authors. During the review phase, each submitted paper is published on a discussion forum whose access is restricted to the authors and to all the PC members not declaring a conflict of interest. The PC members post comments and questions that the authors reply to. For the first time, the 2016 edition of ICE included a feature targeting review transparency: reviews of accepted papers were made public on the workshop website and workshop participants in particular were able to access them during the workshop. Each paper was reviewed by three PC members, and altogether nine papers were accepted for publication (the workshop also featured three brief announcements which are not part of this volume). We were proud to host two invited talks, by Alexandra Silva and Uwe Nestmann. The abstracts of these two talks are included in this volume together with the regular papers
Human and Robot Hands: Sensorimotor Synergies to Bridge the Gap Between Neuroscience and Robotics
No full textThe control of the many degrees of freedom of the hand through functional modules (hand synergies) has been proposed as a potentially useful model to describe how the hand can maintain postures while being able to rapidly change its configuration to accomplish a wide range of tasks. However, whether and to what extent synergies are actually encoded in motor cortical areas is still debated. A direct encoding of hand synergies is suggested by electrophysiological studies in nonhuman primates, but the evidence in humans resulted, so far, partial and indirect. In this chapter, we review the organization of the brain network that controls hand posture in humans and present preliminary results of a functional Magnetic Resonance Imaging (fMRI) on the encoding of synergies at a cortical level to control hand posture in humans
The spreading of misinformation online
No full textThe wide availability of user-provided content in online social media facilitates the aggregation of people around common interests, worldviews, and narratives. However, the World Wide Web (WWW) also allows for the rapid dissemination of unsubstantiated rumors and conspiracy theories that often elicit rapid, large, but naive social responses such as the recent case of Jade Helm 15––where a simple military exercise turned out to be perceived as the beginning of a new civil war in the United States. In this work, we address the determinants governing misinformation spreading through a thorough quantitative analysis. In particular, we focus on how Facebook users consume information related to two distinct narratives: scientific and conspiracy news. We find that, although consumers of scientific and conspiracy stories present similar consumption patterns with respect to content, cascade dynamics differ. Selective exposure to content is the primary driver of content diffusion and generates the formation of homogeneous clusters, i.e., “echo chambers.” Indeed, homogeneity appears to be the primary driver for the diffusion of contents and each echo chamber has its own cascade dynamics. Finally, we introduce a data-driven percolation model mimicking rumor spreading and we show that homogeneity and polarization are the main determinants for predicting cascades’ size
On the Curse of Dimensionality in the Ritz Method
No full textIt is shown that the classical Ritz method of the calculus of variations suffers from the “curse of dimensionality,” i.e., an exponential growth, as a function of the number of variables, of the dimension a linear subspace needs in order to achieve a desired relative improvement in the accuracy of approximation of the optimal solution value. The proof is constructive and is obtained by exhibiting a family of infinite-dimensional optimization problems for which this happens, namely those with quadratic functional and spherical constraint. The results provide a theoretical motivation for the search of alternative solution methods, such as the so-called “extended Ritz method,” to deal with the curse of dimensionality