A bayesian approach to simultaneously recover camera pose and non-rigid shape from monocular images

© . This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/In this paper we bring the tools of the Simultaneous Localization and Map Building (SLAM) problem from a rigid to a deformable domain and use them to simultaneously recover the 3D shape of non-rigid surfaces and the sequence of poses of a moving camera. Under the assumption that the surface shape may be represented as a weighted sum of deformation modes, we show that the problem of estimating the modal weights along with the camera poses, can be probabilistically formulated as a maximum a posteriori estimate and solved using an iterative least squares optimization. In addition, the probabilistic formulation we propose is very general and allows introducing different constraints without requiring any extra complexity. As a proof of concept, we show that local inextensibility constraints that prevent the surface from stretching can be easily integrated. An extensive evaluation on synthetic and real data, demonstrates that our method has several advantages over current non-rigid shape from motion approaches. In particular, we show that our solution is robust to large amounts of noise and outliers and that it does not need to track points over the whole sequence nor to use an initialization close from the ground truth.Peer ReviewedPostprint (author's final draft

Expansion of the current methodology for the study of the short-term liquidity problems in a sector

Purpose: The aim of this work consists of defining and applying a new methodology for the calculation of short-term financial ratios that more reliably approximate the solvency of a sector. Design/methodology: We begin with a classic sector analysis and propose the creation of ratios that limit the debt repayment on an individual level and that do not imply the compensation of aggregate balances, as occurs with the current formulas of calculation. Findings: The new methodology more reliably approximates the solvency of a sector by being able to estimate with greater precision its global capacity for short-term debt repayment. Research limitations: The limitations to the proposed sector ratios are the same as the limitations of the customary individual ratios. Therefore, to offer an example, the ratios do not correct the assumption that the only source of resources to meet current liabilities is made up by available and liquid assets. In other words, no new tools are proposed to include future income from sales by the companies. Practical implications: To be able to study the solvency of the different sectors that make up the economy with more uniform criteria. Social implications: The information provided by the new ratios obtained in this work proves to be relevant information in the case of wanting to determine the degree of dependence of companies in a sector on financial institutions, or in the case of wanting to determine the degree of dependence on aid in a subsidized sector. Originality/value: The proposal of new tools that go beyond the current limitations.Peer Reviewe

Sequential non-rigid structure from motion using physical priors

© 20xx IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.We propose a new approach to simultaneously recover camera pose and 3D shape of non-rigid and potentially extensible surfaces from a monocular image sequence. For this purpose, we make use of the Extended Kalman Filter based Simultaneous Localization And Mapping (EKF-SLAM) formulation, a Bayesian optimization framework traditionally used in mobile robotics for estimating camera pose and reconstructing rigid scenarios. In order to extend the problem to a deformable domain we represent the object's surface mechanics by means of Navier's equations, which are solved using a Finite Element Method (FEM). With these main ingredients, we can further model the material's stretching, allowing us to go a step further than most of current techniques, typically constrained to surfaces undergoing isometric deformations. We extensively validate our approach in both real and synthetic experiments, and demonstrate its advantages with respect to competing methods. More specifically, we show that besides simultaneously retrieving camera pose and non-rigid shape, our approach is adequate for both isometric and extensible surfaces, does not require neither batch processing all the frames nor tracking points over the whole sequence and runs at several frames per second.Peer ReviewedPostprint (author's final draft

Real-time 3D reconstruction of non-rigid shapes with a single moving camera

© . This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/This paper describes a real-time sequential method to simultaneously recover the camera motion and the 3D shape of deformable objects from a calibrated monocular video. For this purpose, we consider the Navier-Cauchy equations used in 3D linear elasticity and solved by finite elements, to model the time-varying shape per frame. These equations are embedded in an extended Kalman filter, resulting in sequential Bayesian estimation approach. We represent the shape, with unknown material properties, as a combination of elastic elements whose nodal points correspond to salient points in the image. The global rigidity of the shape is encoded by a stiffness matrix, computed after assembling each of these elements. With this piecewise model, we can linearly relate the 3D displacements with the 3D acting forces that cause the object deformation, assumed to be normally distributed. While standard finite-element-method techniques require imposing boundary conditions to solve the resulting linear system, in this work we eliminate this requirement by modeling the compliance matrix with a generalized pseudoinverse that enforces a pre-fixed rank. Our framework also ensures surface continuity without the need for a post-processing step to stitch all the piecewise reconstructions into a global smooth shape. We present experimental results using both synthetic and real videos for different scenarios ranging from isometric to elastic deformations. We also show the consistency of the estimation with respect to 3D ground truth data, include several experiments assessing robustness against artifacts and finally, provide an experimental validation of our performance in real time at frame rate for small mapsPeer ReviewedPostprint (author's final draft

Probabilistic simultaneous pose and non-rigid shape recovery

We present an algorithm to simultaneously recover non-rigid shape and camera poses from point correspondences between a reference shape and a sequence of input images. The key novel contribution of our approach is in bringing the tools of the probabilistic SLAM methodology from a rigid to a deformable domain. Under the assumption that the shape may be represented as a weighted sum of deformation modes, we show that the problem of estimating the modal weights along with the camera poses, may be probabilistically formulated as a maximum a posterior estimate and solved using an iterative least squares optimization. An extensive evaluation on synthetic and real data, shows that our approach has several significant advantages over current approaches, such as performing robustly under large amounts of noise and outliers, and neither requiring to track points over the whole sequence nor initializations close from the ground truth solution.Postprint (author’s final draft

Climate change adaptation strategies in Sub-Saharan Africa: foundations for the future

Many institutions across sub-Saharan Africa (SSA) and many funding agencies that support them are currently engaged in initiatives that are targeted towards adapting rainfed agriculture to climate change. This does, however, present some very real and complex research and policy challenges. Given to date the generally low impact of agricultural research across SSA on improving the welfare of rainfed farmers under current climatic conditions, a comprehensive strategy is required if the considerably more complex challenge of adapting agriculture to future climate change is to bear fruit. In articulating such a strategy, it is useful to consider the criteria by which current successful initiatives should be judged

Using a new high-throughput video-tracking platform to assess behavioural changes in Daphnia magna exposed to neuro-active drugs

© 2019. ElsevierOne of the major challenges that faces today regulatory risk assessment is to speed up the way of assessing threshold sublethal detrimental effects of existing and new chemical products. Recently advances in imaging allows to monitor in real time the behaviour of individuals under a given stress. Light is a common stress for many different organisms. Fish larvae and many invertebrate species respond to light altering their behaviour. The water flea Daphnia magna as many other zooplanktonic species has a marked diel vertical phototactic swimming behaviour against light due to fish predation. The aim of this study was to develop a high throughput image analysis to study changes in the vertical swimming behaviour to light of D. magna first reproductive adult females exposed to 0.1 and 1 µg/L of four psychiatric drugs: diazepam, fluoxetine, propranolol and carbamazepine during their entire life. Experiments were conducted using a new custom designed vertical oriented four 50 mL chamber device controlled by the Noldus software (Netherlands). Changes in speed, preferred area (bottom vs upper areas) and animal aggregation were analysed using groups of animals under consecutive periods of dark and apical light stimulus of different intensities. Obtained results indicated that light intensity increased the speed but low light intensities allowed to better discriminate individual responses to the studied drugs. The four tested drugs decreased the response of exposed organisms to light: individuals move less, were closer to the bottom and at low light intensities were closer each other. At high light intensities, however, exposed individuals were less aggregated. Propranolol, carbamazepine and fluoxetine were the compounds effecting most the behaviour. Our results indicated that psychiatric drugs at environmental relevant concentrations alter the vertical phototactic behaviour of D. magna individuals and that it is possible to develop appropriate high-throughput image analysis devices to measure those responses.Peer ReviewedPostprint (author's final draft

Clinical presentation of calmodulin mutations: the International Calmodulinopathy Registry

Calmodulin; Cardiomyopathies; Neurological disordersCalmodulina; Miocardiopatías; Trastornos neurológicosCalmodulina; Miocardiopaties; Trastorns neurològicsAims: Calmodulinopathy due to mutations in any of the three CALM genes (CALM1-3) causes life-threatening arrhythmia syndromes, especially in young individuals. The International Calmodulinopathy Registry (ICalmR) aims to define and link the increasing complexity of the clinical presentation to the underlying molecular mechanisms. Methods and results: The ICalmR is an international, collaborative, observational study, assembling and analysing clinical and genetic data on CALM-positive patients. The ICalmR has enrolled 140 subjects (median age 10.8 years [interquartile range 5-19]), 97 index cases and 43 family members. CALM-LQTS and CALM-CPVT are the prevalent phenotypes. Primary neurological manifestations, unrelated to post-anoxic sequelae, manifested in 20 patients. Calmodulinopathy remains associated with a high arrhythmic event rate (symptomatic patients, n = 103, 74%). However, compared with the original 2019 cohort, there was a reduced frequency and severity of all cardiac events (61% vs. 85%; P = .001) and sudden death (9% vs. 27%; P = .008). Data on therapy do not allow definitive recommendations. Cardiac structural abnormalities, either cardiomyopathy or congenital heart defects, are present in 30% of patients, mainly CALM-LQTS, and lethal cases of heart failure have occurred. The number of familial cases and of families with strikingly different phenotypes is increasing. Conclusion: Calmodulinopathy has pleiotropic presentations, from channelopathy to syndromic forms. Clinical severity ranges from the early onset of life-threatening arrhythmias to the absence of symptoms, and the percentage of milder and familial forms is increasing. There are no hard data to guide therapy, and current management includes pharmacological and surgical antiadrenergic interventions with sodium channel blockers often accompanied by an implantable cardioverter-defibrillator.The ICalmR is one of the registries supported by ERN GUARD-Heart. This research was supported by the Italian Ministry of Health Ricerca Corrente ‘Registro internazionale delle calmodulinopatie’ to L.C., F.D., P.J.S., M.C.K., and C.S.; by the 2019-ATESP-0045 Fondo di Ateneo Quota Competitiva to L.C.; and partially by the Fondation Leducq grant 18CVD05 ‘Towards Precision Medicine with Human iPSCs for Cardiac Channelopathies’ to L.C., M.-C.K., L.S., and P.J.S. J.B., L.C., and P.J.S. were partially supported by the European Joint Programme on Rare Diseases: LQTS-NEXT grant. R.H. was supported by the Canadian Institutes of Health Research, the Heart and Stroke Foundation of Canada, The Labatt Family Heart Centre, the Cartwright Family Fellowship, the Carter Heart Arrhythmia Trainee Fund and the Caitlin Elizabeth Morris fund. J.P.K. was supported by the Medical Research Council (MRC) Clinical Academic Research Partnership (CARP) Award (MR/T024062/1). G.R.W. was supported by an NIH K23HL130554 grant. A.A.M.W. was supported by the Netherlands Cardiovascular Research Initiative (CVON PREDICT-2). M.J.A. was supported in part by the Mayo Clinic Windland Smith Rice Comprehensive Sudden Cardiac Death Program. M.T.O. was supported in part by the Danish Independent Research Council (Grant no. 2032–00333B) and the Lundbeck Foundation (Grant no. R324-2019-1933). H.K.J. was supported by the Novo Nordisk Foundation (Grant NNF 18OC0031258)

Session 1. Videogames

Videogame localization: from development to the end user experience / Itziar Zorrakin-Goikoetxea (University of the Basque Country) ; There is a place for accessibility in the games / Victória Albuquerque Silva (Universidade de Brasília) ; Fun for all: exploring new ways to improve game accessibility for blind players / María Eugenia Larreina (Universitat Autònoma de Barcelona), Carme Mangiron (Universitat Autònoma de Barcelona) ; You have rules… so what? Neologisms and anglicisms in video games localized for the French-Canadian market / Julie Pigeon (Université du Québec en Outaouais). Chair: Estel-la Oncins (Universitat Autònoma de Barcelona

El número borroso triangular "ratio acid-test mínima"

Se da a conocer un nuevo modelo matemático que proporciona un número borroso triangular para establecer el valor de la ratio acid-test mínima en un sector económico determinado. Se presenta una metodología basada en los datos históricos de las empresas de un sector que permite determinar el valor de la ratio acidtest mínima de supervivencia financiera en dicho sector