Wall motion estimation in intracranial aneurysms

The quantification of wall motion in cerebral aneurysms is becoming important owing to its potential connection to rupture, and as a way to incorporate the effects of vascular compliance in computational fluid dynamics (CFD) simulations.Most of papers report values obtained with experimental phantoms, simulated images, or animal models, but the information for real patients is limited. In this paper, we have combined non-rigid registration (IR) with signal processing techniques to measure pulsation in real patients from high frame rate digital subtraction angiography (DSA). We have obtained physiological meaningful waveforms with amplitudes in therange 0mm-0.3mm for a population of 18 patients including ruptured and unruptured aneurysms. Statistically significant differences in pulsation were found according to the rupture status, in agreement with differences in biomechanical properties reported in the literature.

Spectral efficiency in reference-signal-assisted low-power wireless communication

Expressions relating spectral efficiency, power and Doppler spectrum are derived for low-power Rayleighfaded wireless channels with proper complex signaling. Noside information on the state of the channel is assumed at the receiver. Rather, periodic reference signals are postulated inaccordance with the functioning of most wireless systems. In contrast with most previous studies, which relied on block-fading channel models, a continuous-fading model is adopted. This embeds the Doppler spectrum directly in thederived expressions thereby imbuing them with practical significance.

Coupling digital and physical worlds in an AR magic show performance: lessons learned

“Magic for a Pixeloscope” is a one hour show conceived to berepresented in a theater scenario that merges mixed and augmented reality (MR/AR) and full-body interaction with classical magic to create new tricks. The show was conceived by an interdisciplinary team composed by a magician, twointeraction designers, a theater director and a stage designer. Themagician uses custom based hardware and software to createnew illusions which are a starting point to explore new languagefor magical expression. In this paper we introduce a conceptualframework used to inform the design of different tricks; weexplore the design and production of some tricks included in theshow and we describe the feedback received on the world premiere and some of the conclusions obtained.

O fotojornalismo depois da fotografia: Modelos de configuração da cadeia produtiva do fotojornalismo em tempos de convergência digital

This research report concerns about the post-doctoral activities, conducted betweenSeptember 2010 and March 2011 at the University Pompeu Fabra, Barcelona. It comes to identify the consequences of the convergence phenomenon on photojournalism.Thus, in a more general approach, the effort is to to recovery the structural elements of the convergence concept in journalism. It aims to map, as well, the current debates about the repositioning of photographic practices linked to the news produced in a widespread adoption of digital devices in contemporary workflow. It is also specified,the analysis of photographic collectives as a result of the convergence frameworkapplied to photojournalism; the debate on ways of funding; alternatives facing thealleged crisis of press photography and, finally, proposes to create qualifying stages ofdevelopment of photojournalism in the digital age as well as the proposition of hypotheses concerning the structure of the productive routines. In addition, we present three cases to be analyzed in order to explore and verify the occurrence ofcharacteristics that may identify the object of research in the state of practice. Finally,we work in a series of conclusions, revisiting the main hypotheses. With this strategy, ispossible to define an sequence of analysis capable of addressing the characteristics present in the studied cases and other ones in future, thus, be able to affirm this stage as a step, in the continuous historical course of photojournalism.

Echo-time independent signal modulations for strongly coupled systems in triple echo localization schemes: an extension of S-PRESS editing.

The double spin-echo point resolved spectroscopy sequence (PRESS) is a widely used method and standard in clinical MR spectroscopy. Existence of important J-modulations at constant echo times, depending on the temporal delays between the rf-pulses, have been demonstrated recently for strongly coupled spin systems and were exploited for difference editing, removing singlets from the spectrum (strong-coupling PRESS, S-PRESS). A drawback of this method for in vivo applications is that large signal modulations needed for difference editing occur only at relatively long echo times. In this work we demonstrate that, by simply adding a third refocusing pulse (3S-PRESS), difference editing becomes possible at substantially shorter echo times while, as applied to citrate, more favorable lineshapes can be obtained. For the example of an AB system an analytical description of the MR signal, obtained with this triple refocusing sequence (3S-PRESS), is provided.

Fluência digital e uso de ambientes virtuais: caracterização de alunos de enfermagem

O objetivo do estudo foi caracterizar o perfil de licenciandos de enfermagem, identificar a fluência digital, o conhecimento, a habilidade e o interesse no uso de ambientes virtuais de aprendizagem. Trata-se de uma pesquisa quantitativa, exploratório-descritiva realizada com 51 licenciandos de enfermagem por meio de questionário. Dos participantes do estudo 51 (100%) afirmam ter conhecimento em informática, sendo que 26 (49%) indicam um nível intermediário; 47 (92%) fazem uso diário da Internet; 51 (100%) navegam em redes sociais e possuem e-mail; 51(100%) utilizam MSN e 32 (62,7%) Skype; 41 (82%) acessam Chats, 33 (64,7%) Fóruns de discussão e 22 (43%) Blogs; 33 (64,7%) utilizam frequentemente o Moodle e 26 (51%) o COL; e a grande maioria (45- 88,2%) relatou interesse no uso de ambientes virtuais de aprendizagem. Os alunos foram considerados fluentes digitais e apresentaram conhecimento, habilidade e expressivo interesse no uso de ambientes virtuais de aprendizagem em sua formação acadêmica.

Digital storytelling: un’applicazione didattica per ripensare ai media attraverso i media

El presente trabajo de investigación propone un proyecto de investigación centrado en los pre-adolescentes para estudiar, a través deautobiografías digitales (digital storytelling, DST) producidas por ellos, laspracticas cultural-medial y las representaciones que ellos han construido sobre los medios, en relación con los contextos de uso significativos, como el hogar, la escuela o su grupo de par. Los medios forman parte de las actividades cotidianas de los niños quien los emplean en prácticas de socialización, aprendizaje, juego y de construcción de la identidad y del conocimiento. Los digital storytelling,insertados en el contexto escolar, serán empleados como metodología didácticapara la adquisición de competencias tecnológicas y como instrumento de lainvestigación. Los DST, como practica cultural de los chicos, constituirán nuestrocampo para la observación de las modalidades de uso de los medios por parte delos jóvenes y sus capacidad de recombinar lenguajes y construir contenidos. LosDST proporcionaran, además, la posibilidad de acceder al universo simbólicoinfantil para comprender el significado que las tecnologías tienen en sus cotidianidad

Especificitats de la narrativa audiovisual informativa a Internet: anàlisi de les rutines de producció i dels vídeos produïts per La Vanguardia Digital, VilaWeb i 3cat24.cat

El present projecte d’investigació és el treball de recerca del Doctorat en Comunicació Pública (bienni 2007-2009) i es proposa de desenvolupar-lo com a tesi doctoral. Vol estudiar les especificitats de la narrativa audiovisual informativa a Internet de tres mitjans digitals decomunicació catalans. Per a fer-ho es proposa una metodologia qualitativa dividida en dos blocs: el primer, a partir de l'observació, entrevistes en profunditat i enquestes, vol investigar les novesrutines de producció audiovisual en aquests tres mitjans, condicionades per un nou entorn digital; el segon, a partir de la narratologia, vol analitzar els efectes d'aquestes rutines i d'aquest nou entorn enel producte audiovisual resultant

Relatedness influences signal reliability in evolving robots.

Communication is an indispensable component of animal societies, yet many open questions remain regarding the factors affecting the evolution and reliability of signalling systems. A potentially important factor is the level of genetic relatedness between signallers and receivers. To quantitatively explore the role of relatedness in the evolution of reliable signals, we conducted artificial evolution over 500 generations in a system of foraging robots that can emit and perceive light signals. By devising a quantitative measure of signal reliability, and comparing independently evolving populations differing in within-group relatedness, we show a strong positive correlation between relatedness and reliability. Unrelated robots produced unreliable signals, whereas highly related robots produced signals that reliably indicated the location of the food source and thereby increased performance. Comparisons across populations also revealed that the frequency for signal production-which is often used as a proxy of signal reliability in empirical studies on animal communication-is a poor predictor of signal reliability and, accordingly, is not consistently correlated with group performance. This has important implications for our understanding of signal evolution and the empirical tools that are used to investigate communication.

Desarrollo de Surrogates para la representación dinámica de la información digital

El volumen de información a la que un usuario tiene acceso en Internet esenorme. La representación de la misma ha ido evolucionando a lo largo del tiempo a lavez que se han establecido reglas, recomendaciones y directrices que conforman toda una ingeniería de diseño de interfaces con el propósito de mejorar la representación e interacción entre el usuario y el ordenador. Aún así, hay que ir evolucionando en la manera de tratar esta representación de la información ya que Internet es un espacio donde afloran, día tras día, nuevas tecnologías y servicios.De hecho, en este proyecto trataremos de mejorar la representación de lainformación mediante unos objetos que llamaremos surrogates o sustitutos. Como sunombre indica, estos sustitutos serán la representación de los elementos a reemplazar y cuya función podríamos calificar como de “puerta de enlace”. Dichos objetos estaránformados por elementos propios de la información a la que representan con el objetivo de que el usuario identifique de una manera más rápida y sencilla esta información.En definitiva, desarrollaremos unos surrogates que puedan ser usados endiferentes interfaces independientemente de la tecnología que se haya empleado para sudesarrollo y dotándolos de una serie de características y métodos con el fin de mejorar la interacción entre el usuario y la información.

Economia digital : una sortida per a múltiples sistemes comercials

Economia Digital: Una sortida per a múltiples sistemes comercials, és un treball de recerca que tracta sobre el comerç electrònic en tots els seus aspectes, partint d’un anàlisi teòric que estableix les bases d’aquest sistema comercial; seguit d’un estudi de dos casos concrets d’empreses que han introduït Internet en la seva activitat. Per una banda, una d’aquestes empreses, Destil·leries Julián Segarra, s’ha servit de les noves tecnologies, amb un ús publicitari, per tal de donar-se a conèixer però sense oferir la possibilitat de venda online. D’altra banda, Surfdevils S.L. no només utilitza els recursos que ofereix la xarxa de manera informativa, sinó que va més enllà i permet adquirir els seus productes mitjançant el seu espai web. A més es realitza un breu estudi sobre els hàbits de compra per Internet, mitjançant una enquesta efectuada a una mostra de la població.Tot aquest estudi, serveix per arribar a la conclusió que introduir el comerç electrònic dins del seu funcionament és rentable per a les empreses i beneficiós pels consumidors, ja que els ofereix la possibilitat d’adquirir els productes en un mercat més ampli, transparent i competitiu.

Dual-wavelength digital holographic microscopy with sub-nanometer axial accuracy

We present dual-wavelength Digital Holographic Microscopy (DHM) measurements on a certified 8.9 nm high Chromium thin step sample and demonstrate sub-nanometer axial accuracy. We introduce a modified DHM Reference Calibrated Hologram (RCH) reconstruction algorithm taking into account amplitude contributions. By combining this with a temporal averaging procedure and a specific dual-wavelength DHM arrangement, it is shown that specimen topography can be measured with an accuracy, defined as the axial standard deviation, reduced to at least 0.9 nm. Indeed, it is reported that averaging each of the two wavefronts recorded with real-time dual-wavelength DHM can provide up to 30% spatial noise reduction for the given configuration, thanks to their non-correlated nature. ©2008 COPYRIGHT SPIE

Perfil, competências e fluência digital dos enfermeiros do Programa de Aprimoramento Profissional

Estudo descritivo, exploratório, realizado na cidade de São Paulo, que objetivou identificar o perfil, as competências e a fluência digital do enfermeiro aprimorando para uso da tecnologia no trabalho. A população composta por 60 aprimorandos do Programa de Aprimoramento Profissional respondeu um questionário com dados sobre o perfil, a fluência digital e as competências profissionais. Verificou-se que 95,0% dos participantes eram do sexo feminino, 61,7% na faixa etária entre 23 a 25 anos, 75,0% graduados em escolas públicas, 58,3% cursando enfermagem cardiovascular, 98,3% teve contato com recursos computacionais na graduação; 100,0% possuía computador em casa; 86,7% acessava a internet diariamente; 96,7% utilizava o Messenger e 58,3% apresentava grau intermediário de conhecimento e habilidade em informática. As competências profissionais requeridas frente à tecnologia referiram-se ao saber ser inovador, criativo, atualizado para conhecer e gerenciar programas e saber utilizar os recursos tecnológicos.

Effects of phylogenetic signal on ancestral state reconstruction.

One of the standard tools used to understand the processes shaping trait evolution along the branches of a phylogenetic tree is the reconstruction of ancestral states (Pagel 1999). The purpose is to estimate the values of the trait of interest for every internal node of a phylogenetic tree based on the trait values of the extant species, a topology and, depending on the method used, branch lengths and a model of trait evolution (Ronquist 2004). This approach has been used in a variety of contexts such as biogeography (e.g., Nepokroeff et al. 2003, Blackburn 2008), ecological niche evolution (e.g., Smith and Beaulieu 2009, Evans et al. 2009) and metabolic pathway evolution (e.g., Gabaldón 2003, Christin et al. 2008). Investigations of the factors affecting the accuracy with which ancestral character states can be reconstructed have focused in particular on the choice of statistical framework (Ekman et al. 2008) and the selection of the best model of evolution (Cunningham et al. 1998, Mooers et al. 1999). However, other potential biases affecting these methods, such as the effect of tree shape (Mooers 2004), taxon sampling (Salisbury and Kim 2001) as well as reconstructing traits involved in species diversification (Goldberg and Igić 2008), have also received specific attention. Most of these studies conclude that ancestral character states reconstruction is still not perfect, and that further developments are necessary to improve its accuracy (e.g., Christin et al. 2010). Here, we examine how different estimations of branch lengths affect the accuracy of ancestral character state reconstruction. In particular, we tested the effect of using time-calibrated versus molecular branch lengths and provide guidelines to select the most appropriate branch lengths to reconstruct the ancestral state of a trait.

Sequence determinants of a microtubule tip localization signal (MtLS).

Microtubule plus-end-tracking proteins (+TIPs) specifically localize to the growing plus-ends of microtubules to regulate microtubule dynamics and functions. A large group of +TIPs contain a short linear motif, SXIP, which is essential for them to bind to end-binding proteins (EBs) and target microtubule ends. The SXIP sequence site thus acts as a widespread microtubule tip localization signal (MtLS). Here we have analyzed the sequence-function relationship of a canonical MtLS. Using synthetic peptide arrays on membrane supports, we identified the residue preferences at each amino acid position of the SXIP motif and its surrounding sequence with respect to EB binding. We further developed an assay based on fluorescence polarization to assess the mechanism of the EB-SXIP interaction and to correlate EB binding and microtubule tip tracking of MtLS sequences from different +TIPs. Finally, we investigated the role of phosphorylation in regulating the EB-SXIP interaction. Together, our results define the sequence determinants of a canonical MtLS and provide the experimental data for bioinformatics approaches to carry out genome-wide predictions of novel +TIPs in multiple organisms.