Kernel-PCA data integration with enhanced interpretability

Background Nowadays, combining the different sources of information to improve the biological knowledge available is a challenge in bioinformatics. One of the most powerful methods for integrating heterogeneous data types are kernel-based methods. Kernel-based data integration approaches consist of two basic steps: firstly the right kernel is chosen for each data set; secondly the kernels from the different data sources are combined to give a complete representation of the available data for a given statistical task. Results We analyze the integration of data from several sources of information using kernel PCA, from the point of view of reducing dimensionality. Moreover, we improve the interpretability of kernel PCA by adding to the plot the representation of the input variables that belong to any dataset. In particular, for each input variable or linear combination of input variables, we can represent the direction of maximum growth locally, which allows us to identify those samples with higher/lower values of the variables analyzed. Conclusions The integration of different datasets and the simultaneous representation of samples and variables together give us a better understanding of biological knowledge.

Correlations between Vocal Input and Visual Response Apparently Enhance Presence in a Virtual Environment

This work investigates novel alternative means of interaction in a virtual environment (VE).We analyze whether humans can remap established body functions to learn to interact with digital information in an environment that is cross-sensory by nature and uses vocal utterances in order to influence (abstract) virtual objects. We thus establish a correlation among learning, control of the interface, and the perceived sense of presence in the VE. The application enables intuitive interaction by mapping actions (the prosodic aspects of the human voice) to a certain response (i.e., visualization). A series of single-user and multiuser studies shows that users can gain control of the intuitive interface and learn to adapt to new and previously unseen tasks in VEs. Despite the abstract nature of the presented environment, presence scores were generally very high.

Empirical study of correlated survival times for recurrent events with proportional hazards margins and the effect of correlation and censoring.

Background: In longitudinal studies where subjects experience recurrent incidents over a period of time, such as respiratory infections, fever or diarrhea, statistical methods are required to take into account the within-subject correlation. Methods: For repeated events data with censored failure, the independent increment (AG), marginal (WLW) and conditional (PWP) models are three multiple failure models that generalize Cox"s proportional hazard model. In this paper, we revise the efficiency, accuracy and robustness of all three models under simulated scenarios with varying degrees of within-subject correlation, censoring levels, maximum number of possible recurrences and sample size. We also study the methods performance on a real dataset from a cohort study with bronchial obstruction. Results: We find substantial differences between methods and there is not an optimal method. AG and PWP seem to be preferable to WLW for low correlation levels but the situation reverts for high correlations. Conclusions: All methods are stable in front of censoring, worsen with increasing recurrence levels and share a bias problem which, among other consequences, makes asymptotic normal confidence intervals not fully reliable, although they are well developed theoretically.

Les claus persuasives en la comunicació web de les destinacions enoturístiques

El següent projecte presenta una proposta de recerca per a una futura tesi doctoral. Aquest, pretén estudiar quins són els factors clau que s‟han de contemplar en la comunicació web de les destinacions enoturístiques per tal d‟establir una comunicació eficaç, persuasiva i atractiva per als seus públics. També pretén contribuir a establir uns principis comunicatius que afavoreixin la creació de sinèrgies entre les destinacions enoturístiques europees. L‟estudi es planteja la recerca de la comunicació web a tres nivells: la font, el missatge i la recepció d‟aquest. Amb aquesta finalitat, es proposa una triangulació de mètodes qualitatius i quantitatius basada en la utilització de les tècniques de revisió documental, d‟anàlisi de contingut web, entrevistes en profunditat, enquestes i l‟experimentació. L‟estudi permetrà obtenir un recull de bones pràctiques per a optimitzar la comunicació enoturística a través del web; una contribució teòrica des d‟una perspectiva comunicativa útil per a l‟evolució del sector

La dissolució de l'educand. Assaig d'arqueologia de la novel·la alemanya de formació

Des de la Poètica d'Aristotil (segle IV a. C .. ), que assimila la creació artística a la mímesi, acostumem a oposar els termes de 'ficció' i de 'realitat' com s'oposen la simulació d'aparences (múltiples) a la identitat d'allò que és ver ( i per tant, u). Aquesta aproximació lògica a la relació existent entre l'escriptura i l'ordre de representació de les coses, o entre les dimensions simbòliques de la raó estètica i els seus referents reals, vincula, ho sabem, les paraules i les coses d'una manera molt complexa .

Reinforcement learning utilizes proxemics: an avatar learns to manipulate the position of people in immersive virtual reality

A reinforcement learning (RL) method was used to train a virtual character to move participants to a specified location. The virtual environment depicted an alleyway displayed through a wide field-of-view head-tracked stereo head-mounted display. Based on proxemics theory, we predicted that when the character approached within a personal or intimate distance to the participants, they would be inclined to move backwards out of the way. We carried out a between-groups experiment with 30 female participants, with 10 assigned arbitrarily to each of the following three groups: In the Intimate condition the character could approach within 0.38m and in the Social condition no nearer than 1.2m. In the Random condition the actions of the virtual character were chosen randomly from among the same set as in the RL method, and the virtual character could approach within 0.38m. The experiment continued in each case until the participant either reached the target or 7 minutes had elapsed. The distributions of the times taken to reach the target showed significant differences between the three groups, with 9 out of 10 in the Intimate condition reaching the target significantly faster than the 6 out of 10 who reached the target in the Social condition. Only 1 out of 10 in the Random condition reached the target. The experiment is an example of applied presence theory: we rely on the many findings that people tend to respond realistically in immersive virtual environments, and use this to get people to achieve a task of which they had been unaware. This method opens up the door for many such applications where the virtual environment adapts to the responses of the human participants with the aim of achieving particular goals.

Drift and ownership toward a distant virtual body.

In body ownership illusions participants feel that a mannequin or virtual body (VB) is their own. Earlier results suggest that body ownership over a body seen from behind in extra personal space is possible when the surrogate body is visually stroked and tapped on its back, while spatially and temporal synchronous tactile stimulation is applied to the participant's back. This result has been disputed with the claim that the results can be explained by self-recognition rather than somatic body ownership. We carried out an experiment with 30 participants in a between-groups design. They all saw the back of a VB 1.2 m in front, that moved in real-time determined by upper body motion capture. All felt tactile stimulation on their back, and for 15 of them this was spatially and temporally synchronous with stimulation that they saw on the back of the VB, but asynchronous for the other 15. After 3 min a revolving fan above the VB descended and stopped at the position of the VB neck. A questionnaire assessed referral of touch to the VB, body ownership, the illusion of drifting forwards toward the VB, and the VB drifting backwards. Heart rate deceleration (HRD) and the amount of head movement during the threat period were used to assess the response to the threat from the fan. Results showed that although referral of touch was significantly greater in the synchronous condition than the asynchronous, there were no other differences between the conditions. However, a further multivariate analysis revealed that in the visuotactile synchronous condition HRD and head movement increased with the illusion of forward drift and decreased with backwards drift. Body ownership contributed positively to these drift sensations. Our conclusion is that the setup results in a contradiction-somatic feelings associated with a distant body-that the brain attempts to resolve by generating drift illusions that would make the two bodies coincide.

La problemàtica psicopedagògica a secundària : alguns elements de particular incidència actual

Aquest article presenta una breu anàlisi de la situació actual de l’Educació Secundària, centrada en vuit punts: els continguts curriculars, els mètodes d’ensenyament-aprenentatge, la motivació de l’alumnat, la motivació del professorat, l’avaluació, la tutoria de grup, la tutoria individual i les relacions escola-família. Com a pistes de futur assenyala cinc aspectes: els espais de trobada escola-família, concretar els valors i conviccions de pares i mestres, l’actuació dels equips interdisciplinaris, la valoració multidimensional del progrés dels alumnes i el rellançament de la tutoria.

Conèixer els estudiants per a millorar la docència: hàbits d'estudi i d'oci dels estudiants de Farmàcia de la UB

En educació superior, l’estudiant no només es prepara per a l’obtenció d’un títol que li permeti accedir al món professional, és un moment en què aprèn a ser autònom emocional i econòmicament, aprèn a conviure amb gent d’orígens i classe diferents, i es desenvolupa com a persona. Conèixer l’opinió dels estudiants en moments cabdals de la seva vida universitària és, en tot cas, interessant. Dos moments, especialment significatius, són l’any de l’arribada, quan són estudiants de nou ingrés i l’any en quefinalitzen els estudis, a punt d’obtenir el títol. Entre aquests dos moments, s’ha produït una transformació en molts aspectes que els ha permès adquirir competències que, sens dubte, els ha fet créixer com a persones. Es presenta l’estudi realitzat a la Facultat de Farmàcia de la UB. Es va prendre com a punt de partida la gestió del temps per a iniciar la reflexió sobre els seus hàbits i preferències d’estudi i oci i com influencien el seu rendiment, primer amb estudiants de nou ingrés i, passats cinc anys, quan la mateixa comunitat d’estudiants estaven a punt de finalitzar els estudis, es va repetir per tal de conèixer els canvis que havien tingut lloc i com ho havien percebut els protagonistes.

Lideratge i funció directiva. Ofici o actitud? (líder, innovador, emprenedor) (autoestima?)

El lideratge és el conjunt de capacitats que una persona té per influir en les persones o en un grup de persones determinat, per a l’assoliment de metes i objectius predeterminats. El líder te la capacitat de prendre la iniciativa, gestionar, convocar, promoure, incentivar, motivar i avaluar a un grup o equip. Capacitat fa referència als recursos i aptituds que té un individu per a exercir una determinada tasca o comesa (no ens diu res de si són innates o adquirides) per tant ens fiquem en un “lio” (habilitats, competències, aptituds, etc.. etc…). Parlem de coneixement. En l’àmbit de l’economia del coneixement “es allò que sabem (encara que no sapiguem que ho sabem) que ens capacita per a l’acció”. Aquí ens tornem a trobar el coneixement innat i el adquirit. En aquest cas, “l’acció” son precisament el que han de fer les persones en relació a un objectiu. En el lideratge la capacitat o coneixement es comportamental i per tant per adquirir-lo cal aprendre comportaments (simulació - estandardització, entrenament, es el mon de l’experiència). Canviar els comportaments es el mes difícil. Per una Escola aniria per formar en el lideratge li aniria millor que estiguéssim parlant de coneixements “memoristics” o de procediment que son molt mes fàcils de formar.

Exercicis de física interactius

El present projecte pretén proposar una alternativa més per afrontar la física de 1r de Batxillerat. El resultat és una web amb una sèrie d'exercicis que mostren una solució implementada amb Box2D.

How to redesign a virtual library website: a case study

This abstract presents how we redesigned, with user-centred design methods, the way we organize and present the content on the UOC Virtual Library website. The content is now offered in a way that is more intuitive, usable and easy to understand, based on criteria of customization, transparency and proximity.The techniques used to achieve these objectives included benchmarking, interviews and focus groups during the user requirement capture phase and user tests to assess the process and results.

Is my hand connected to my body? The impact of body continuity and arm alignment on the virtual hand illusion

When a rubber hand is placed on a table top in a plausible position as if part of a person"s body, and is stroked synchronously with the person"s corresponding hidden real hand, an illusion of ownership over the rubber hand can occur (Botvinick and Cohen 1998). A similar result has been found with respect to a virtual hand portrayed in a virtual environment, a virtual hand illusion (Slater et al. 2008). The conditions under which these illusions occur have been the subject of considerable study. Here we exploited the flexibility of virtual reality to examine four contributory factors: visuo-tactile synchrony while stroking the virtual and the real arms, body continuity, alignment between the real and virtual arms, and the distance between them. We carried out three experiments on a total of 32 participants where these factors were varied. The results show that the subjective illusion of ownership over the virtual arm and the time to evoke this illusion are highly dependent on synchronous visuo-tactile stimulation and on connectivity of the virtual arm with the rest of the virtual body. The alignment between the real and virtual arms and the distance between these were less important. It was found that proprioceptive drift was not a sensitive measure of the illusion, but was only related to the distance between the real and virtual arms.

Reaction-diffusion lattice gas: Theory and computer results

We report on the study of nonequilibrium ordering in the reaction-diffusion lattice gas. It is a kinetic model that relaxes towards steady states under the simultaneous competition of a thermally activated creation-annihilation $(reaction$) process at temperature T, and a diffusion process driven by a heat bath at temperature T?T. The phase diagram as one varies T and T, the system dimension d, the relative priori probabilities for the two processes, and their dynamical rates is investigated. We compare mean-field theory, new Monte Carlo data, and known exact results for some limiting cases. In particular, no evidence of Landau critical behavior is found numerically when d=2 for Metropolis rates but Onsager critical points and a variety of first-order phase transitions.

¿Favorece la publicación en abierto el impacto de los artículos científicos? Un estudio empírico en el ámbito de la medicina intensiva

Peer-reviewed