Visualising Discourse Structure in Interactive Documents

In this paper we introduce a method for generating interactive documents which exploits the visual features of hypertext to represent discourse structure. We explore the consistent and principled use of graphics and animation to support navigation and comprehension of non-linear text, where textual discourse markers do not always work effectively

Solving the Gibbs Problem with Algebraic Projective Geometry

Orbit determination (OD) from three position vectors is one of the classical problems in astrodynamics. Early contributions to this problem were made by J. Willard Gibbs in the late 1800s and OD of this type is known today as ``Gibbs Problem''. There are a variety of popular solutions to the Gibbs problem. While some authors solve for the orbital elements directly, most contemporary discussions are based on a vector analysis approach inspired by Gibbs himself. This work presents a completely different solution to those just described. Although there is nothing wrong with the vector analysis approach, some interesting insights may be gained by considering the problem from the perspective of algebraic projective geometry. Such an algebraic solution is presented here. The OD procedure is based upon a novel and geometrically meaningful solution to the algebraic fitting of an ellipse with a focus at the origin using only three points. Although the final OD result is identical to the classical vector analysis approach pioneered by Gibbs, this new algebraic solution is interesting in its own right

Geometric Solution to the Angles-Only Initial Orbit Determination Problem

Initial orbit determination (IOD) from line-of-sight (i.e., bearing) measurements is a classical problem in astrodynamics. Indeed, there are many well-established methods for performing the IOD task when given three line-of-sight observations at known times. Interestingly, and in contrast to these existing methods, concepts from algebraic geometry may be used to produce a purely geometric solution. This idea is based on the fact that bearings from observers in general position may be used to directly recover the shape and orientation of a three-dimensional conic (e.g., a Keplerian orbit) without any need for knowledge of time. In general, it is shown that five bearings at unknown times are sufficient to recover the orbit -- without the use of any type of initial guess and without the need to propagate the orbit. Three bearings are sufficient for purely geometric IOD if the orbit is known to be (approximately) circular. The method has been tested over different scenarios, including one where extra observations make the system of equations over-determined.Comment: 31 pages excluding back matter, 14 figure

Guest Editorial: Special Issue on Frontiers in Trust Management

Information and Communication Technologies (ICT) are becoming increasingly important in the way we organize our lives, our workplaces and our societies. ICT allows people and organisations, that have never interacted with each other in the past, to initiate new and mutually beneficial businesses across the world. This means that personal and business information is increasingly being communicated across interpersonal, inter-business and international borders. Keeping this information safe and protecting the fragile IT infrastructure from criminals is a growing problem in most societies. Unfortunately, traditional security technologies based on a strong perimeter defence work poorly in an inter-connected world that obeys Metcalfe’s law which states that “the value of a network is proportional to the square of the number of connected users of the system”, i.e., where there is a strong incentive for interactions across the different borders. During the past decade, trust management has emerged as a promising solution to many challenges in networks and distributed systems as well as emerging problems in computer security and privacy. This special issue on “Frontiers in Trust Management” attempts to highlight some of the latest re- search addressing those challenges. It collects a series of papers on trust management issues that extends papers and ideas presented at the Fifth IFIP WG 11.11 International Conference on Trust Management or one of the affiliated workshops in Copenhagen, June 27 – July 1, 2011

Dual Quaternion Ambisonics Array for Six-Degree-of-Freedom Acoustic Representation

Spatial audio methods are gaining a growing interest due to the spread of immersive audio experiences and applications, such as virtual and augmented reality. For these purposes, 3D audio signals are often acquired through arrays of Ambisonics microphones, each comprising four capsules that decompose the sound field in spherical harmonics. In this paper, we propose a dual quaternion representation of the spatial sound field acquired through an array of two First Order Ambisonics (FOA) microphones. The audio signals are encapsulated in a dual quaternion that leverages quaternion algebra properties to exploit correlations among them. This augmented representation with 6 degrees of freedom (6DOF) involves a more accurate coverage of the sound field, resulting in a more precise sound localization and a more immersive audio experience. We evaluate our approach on a sound event localization and detection (SELD) benchmark. We show that our dual quaternion SELD model with temporal convolution blocks (DualQSELD-TCN) achieves better results with respect to real and quaternion-valued baselines thanks to our augmented representation of the sound field. Full code is available at: https://github.com/ispamm/DualQSELD-TCN.Comment: Paper under consideration at Elsevier Pattern Recognition Letter

Pharmacological treatment with inhibitors of nuclear export enhances the antitumor activity of docetaxel in human prostate cancer

Background and aims: Docetaxel (DTX) modestly increases patient survival of metastatic castration-resistant prostate cancer (mCRPC) due to insurgence of pharmacological resistance. Deregulation of Chromosome Region Maintenance (CRM-1)/ exportin-1 (XPO-1)-mediated nuclear export may play a crucial role in this phenomenon. Material and methods: Here, we evaluated the effects of two Selective Inhibitor of Nuclear Export (SINE) compounds, selinexor (KPT-330) and KPT-251, in association with DTX by using 22rv1, PC3 and DU145 cell lines with their. DTX resistant derivatives. Results and conclusions: We show that DTX resistance may involve overexpression of β-III tubulin (TUBB3) and P-glycoprotein as well as increased cytoplasmic accumulation of Foxo3a. Increased levels of XPO-1 were also observed in DTX resistant cells suggesting that SINE compounds may modulate DTX effectiveness in sensitive cells as well as restore the sensitivity to DTX in resistant ones. Pretreatment with SINE compounds, indeed, sensitized to DTX through increased tumor shrinkage and apoptosis by preventing DTX-induced cell cycle arrest. Basally SINE compounds induce FOXO3a activation and nuclear accumulation increasing the expression of FOXO-responsive genes including p21, p27 and Bim causing cell cycle arrest. SINE compounds-catenin and survivin supporting apoptosis. βdown-regulated Cyclin D1, c-myc, Nuclear sequestration of p-Foxo3a was able to reduce ABCB1 and TUBB3 H2AX levels, prolonged γ expression. Selinexor treatment increased DTX-mediated double strand breaks (DSB), and reduced the levels of DNA repairing proteins including DNA PKc and Topo2A. Our results provide supportive evidence for the therapeutic use of SINE compounds in combination with DTX suggesting their clinical use in mCRPC patients

Software para decodificación y análisis de archivos binarios en computadoras navales

En el presente trabajo se detalla el diseño de un software de decodificación de archivos y análisis de grabaciones de eventos navales. Originalmente, las embarcaciones contaban con un programa operativo de características similares, que se ejecutaba sobre las computadoras de 24 bits de abordo. La única interfaz que se disponía era una terminal tipo teletipo donde el operador insertaba comandos y se imprimían los resultados sobre un papel, el cual se utilizaba posteriormente para analizar los resultados del evento naval realizado. Debido a sus múltiples defectos y problemas, se decidió realizar una reingeniería del mismo para poder sustituirlo con un software que se ejecute sobre una PC de uso comercial, brindándole al usuario mayores herramientas y facilidades a través de las tecnologías disponibles en la actualidad.XV Workshop Ingeniería de Software (WIS)Red de Universidades con Carreras en Informática (RedUNCI

Software para decodificación y análisis de archivos binarios en computadoras navales

En el presente trabajo se detalla el diseño de un software de decodificación de archivos y análisis de grabaciones de eventos navales. Originalmente, las embarcaciones contaban con un programa operativo de características similares, que se ejecutaba sobre las computadoras de 24 bits de abordo. La única interfaz que se disponía era una terminal tipo teletipo donde el operador insertaba comandos y se imprimían los resultados sobre un papel, el cual se utilizaba posteriormente para analizar los resultados del evento naval realizado. Debido a sus múltiples defectos y problemas, se decidió realizar una reingeniería del mismo para poder sustituirlo con un software que se ejecute sobre una PC de uso comercial, brindándole al usuario mayores herramientas y facilidades a través de las tecnologías disponibles en la actualidad.XV Workshop Ingeniería de Software (WIS)Red de Universidades con Carreras en Informática (RedUNCI

Software para decodificación y análisis de archivos binarios en computadoras navales

En el presente trabajo se detalla el diseño de un software de decodificación de archivos y análisis de grabaciones de eventos navales. Originalmente, las embarcaciones contaban con un programa operativo de características similares, que se ejecutaba sobre las computadoras de 24 bits de abordo. La única interfaz que se disponía era una terminal tipo teletipo donde el operador insertaba comandos y se imprimían los resultados sobre un papel, el cual se utilizaba posteriormente para analizar los resultados del evento naval realizado. Debido a sus múltiples defectos y problemas, se decidió realizar una reingeniería del mismo para poder sustituirlo con un software que se ejecute sobre una PC de uso comercial, brindándole al usuario mayores herramientas y facilidades a través de las tecnologías disponibles en la actualidad.XV Workshop Ingeniería de Software (WIS)Red de Universidades con Carreras en Informática (RedUNCI

Femtosecond X-ray emission study of the spin cross-over dynamics in haem proteins

In haemoglobin (consisting of four globular myoglobin-like subunits), the change from the low-spin (LS) hexacoordinated haem to the high spin (HS) pentacoordinated domed form upon ligand detachment and the reverse process upon ligand binding, represent the transition states that ultimately drive the respiratory function. Visible-ultraviolet light has long been used to mimic the ligand release from the haem by photodissociation, while its recombination was monitored using time-resolved infrared to ultraviolet spectroscopic tools. However, these are neither element- nor spin-sensitive. Here we investigate the transition state in the case of Myoglobin-NO (MbNO) using femtosecond Fe Kalpha and Kbeta non-resonant X-ray emission spectroscopy (XES) at an X-ray free-electron laser upon photolysis of the Fe-NO bond. We find that the photoinduced change from the LS (S = 1/2) MbNO to the HS (S = 2) deoxy-myoglobin (deoxyMb) haem occurs in ca. 800 fs, and that it proceeds via an intermediate (S = 1) spin state. The XES observables also show that upon NO recombination to deoxyMb, the return to the planar MbNO ground state is an electronic relaxation from HS to LS taking place in ca. 30 ps. Thus, the entire ligand dissociation-recombination cycle in MbNO is a spin cross-over followed by a reverse spin cross-over process