Concevoir des interfaces tangibles et spatiales pour les déficients visuels : pourquoi et comment ?

International audienceMaking geographical maps and graphical representations accessible to visually impaired users is essential. To do so, a variety of approaches exist, whether traditional or technological. Among them, tangible interfaces, although very promising, have not been thoroughly investigated. In this article, we analyze five research prototypes in order to identify the aspects that have to be taken into account when designing spatial tangible interfaces for visually impaired users, and we present the various solutions that have been proposed to address the most commonly encountered problems. In this way we hope to facilitate and support the development and evaluation of spatial tangible interfaces.Rendre les cartes géographiques et les représentations graphiques accessibles aux personnes déficientes visuelles est primordial. Pour cela, de nombreuses solutions existent, qu’elles soient artisanales ou technologiques. Parmi ces dernières, les interfaces tangibles, bien que très prometteuses, ont été très peu étudiées. Dans cet article, nous analysons cinq prototypes issus de la littérature afin d’identifier les facteurs à prendre en compte lors de la conception d’interfaces tangibles et spatiales pour les déficients visuels, et nous présentons les solutions proposées pour répondre aux difficultés techniques fréquemment rencontrées. Nous souhaitons ainsi faciliter et encourager le développement et l’évaluation d’interfaces tangibles et spatiales

Techniques d'interactions sur dispositifs mobiles pour l'aide à l'orientation chez les non-voyants

National audienceLes aides électroniques à la navigation commencent à se diffuser auprès des personnes déficientes visuelles. Elles ont cependant l'inconvénient de ne fournir que des informations sur la destination à atteindre et sur l'itinéraire à suivre, et non sur les éléments présents autour de l'utilisateur tout au long du parcours. Ces dispositifs ne permettent pas aux non-voyants de construire une carte mentale de leur environnement, ce qui est pourtant très utile pour mieux comprendre un déplacement et l'environnement dans lequel il s'est déroulé. Les techniques non-visuelles d'assistance à l'orientation développées sur téléphone mobile dans le cadre de cette étude visent à fournir ces indications manquantes. Elles ont pour objectif de permettre à un utilisateur de localiser trois points de repère prédéfinis, situés dans l'environnement proche (quelques dizaines à centaines de mètres) : à partir de ces informations, l'utilisateur peut déterminer sa position. Trois techniques de présentation de points de repère ont été conçues et développées. Des évaluations préliminaires ont permis de montrer que la connaissance des distances et directions de ces trois points permet à un utilisateur non-voyant, ayant au préalable appris une carte de l'environnement correspondant, de se situer, de s'orienter et d'atteindre une destination dans un environnement ouvert

Enhanced proactive planning approach: a crucial to an improved workers’ safety in Western Nigeria small scale industry

This study evaluated managements’ proactive planning approach (PPA) to enhance safety among workers in South-western Nigeria small scale industry (SSI). The main objective was to rate the managements’ efforts at eliminating risk among their employees. By worker participatory and psychological survey approach, three tools were used; workplace observation (visual), management safety culture (questionnaire) and managers interviews (oral). The survey included 200 workers, 120 supervisors and 80 managers, in 82 SSI. Four steps to a safety proactive action plans (PAP), (looking for clues, prioritization of identified potential hazard, making improvements to eliminate the risk and follow up), were rated by employees on a scale from 0 to 5. Paired t-test was used to appraise the significant difference between the managers’ mean scores rated by the supervisors and other workers. 77.1% of workers and 64.2% supervisors rated their managers as either “not done at all” or “poorly done”. Workers’ scores for managers PPA had statistically significantly lower ratings (mean = 1.09, SEM = 0.22) compared to that of the supervisors rating (mean = 1.55, SEM = 0.32), with t (14) = −1.185, p = 0.784. There is a closed poor performance perception gaps, of managers’ PPA, of the two groups of employees. It can be concluded that safety is not emphasized, by managers of SSI, as overriding priority and this may have contributed to high reported injuries among their workforce. Courses to enhance managements’ understanding for inclusion of safety among the leading priorities becomes necessary. This will reduce work-related risks and promotes occupational safety and health among the group of workers

Les technologies d'assistance pour la qualité de vie et l'autonomie des déficients visuels (TAVIS)

International audienceLe nombre de personnes déficientes visuelles est évalué à 285 millions dans le monde. L'analyse des limitations d'activité et restrictions de participation de ces personnes montre que les nouvelles technologies interactives peuvent apporter des réponses pertinentes pour améliorer leur autonomie. Depuis une décennie, nous avons lancé un ensemble de recherches fondamentales et appliquées permettant de concevoir des dispositifs d'assistance pour les déficients visuels. Les différents domaines concernés sont l'orientation et la mobilité, l'accessibilité des documents (cartes géographiques), l'accessibilité des dispositifs mobiles (smartphones ou tablettes) ou la simulation de la vision prothétique (implant rétinien ou cortical). Afin de travailler de façon pérenne sur la conception de nouvelles technologies d'assistance avec les déficients visuels mais aussi les formateurs et enseignants spécialisés, nous avons créé un laboratoire de recherche commun avec un Centre d'Education Spécialisé pour Déficients Visuel

Haptoglobin genotype and risk of diabetic nephropathy in patients with type 1 diabetes mellitus: a study on a Spanish population

[en] BACKGROUND: Few reports have studied the possible association between the haptoglobin (Hp) genotype and the risk of diabetic nephropathy (DN) in type 1 diabetes (T1D), with conflicting results to date. AIMS: To study whether the 2-2 Hp genotype is associated with an increased risk of overt DN in a Spanish population with T1D. METHODS: We performed a case-control study in a Spanish population. CASES: T1D patients with end-stage renal disease (stage 5 of NKF-KDOQI), awaiting reno-pancreatic transplantation or having already been transplanted (reno-pancreatic or renal alone). CONTROLS: T1D patients, matched for sex and time of diabetes evolution, with preserved renal function and normal urinary albumin excretion. Hp genotyping was done using polymerase chain reaction and electrophoresis. RESULTS: We included 57 cases and 57 controls in the study. There were no statistically significant differences in gender (70% vs. 61% males, p=1.0) or the duration of diabetes (23.0 ± 6.7 vs. 20.8 ± 9.3 years; p=0.1), although the age of onset of diabetes was lower in the cases (14.1 ± 6.8 vs. 17.7 ± 10.1 years, p=0.03). The frequency of genotypes 1-1, 1-2 and 2-2 was 19.3%, 42.1% and 38.6% in cases and 17.5%, 49.1% and 33.4% in controls, respectively, with no statistically significant differences between groups (p=0.8). Conditional logistic regression analysis showed no significant association between genotype 2-2 of Hp and the development of DN (OR 1.14, CI 0.52-2.52). CONCLUSIONS: In our sample of a Spanish population with T1D, no association was found between the Hp genotype and risk of overt DN. [spa] Antecedentes: Pocos trabajos han estudiado la asociación entre el genotipo de la haptoglobina (Hp) y el riesgo de nefropatía diabética (ND) en pacientes con diabetes tipo 1 (DM1), con resultados contradictorios hasta ahora. Objetivos: Estudiar si el genotipo 2-2 de Hp se asocia a un incremento del riesgo de ND en población española con DM1. Métodos: Se diseñó un estudio de casos y controles. CASOS: pacientes con DM1 y enfermedad renal crónica estadio 5 de la NKF-KDOQI, en espera de trasplante reno-pancreático o que han sido trasplantados (reno-pancreático o renal aislado). CONTROLES: pacientes con DM1, apareados por sexo y tiempo de evolución de la diabetes, con función renal y excreción urinaria de albúmina normales. El genotipo de Hp se realizó mediante reacción en cadena de la polimerasa y electroforesis. Resultados: Incluimos 57 casos y 57 controles, sin diferencias estadísticamente significativas en el sexo (70 % frente a 61 % varones, p = 1,0) o duración de la diabetes (23,0 ± 6,7 frente a 20,8 ± 9,3 años; p = 0,1), aunque la edad de inicio de la diabetes fue menor en los casos (14,1 ± 6,8 frente a 17,7 ± 10,1 años, p = 0,03). La frecuencia de genotipos 1-1, 1-2 y 2-2 fue de 19,3 %, 42,1 % y 38,6 % en los casos y de 17,5 %, 49,1 % y 33,4 % en los controles, respectivamente, sin diferencias significativas (p = 0,8). El análisis de regresión logística condicional no mostró asociación entre el genotipo 2-2 de Hp y el desarrollo de ND (OR 1,14, IC 0,52-2,52). Conclusiones: En nuestra muestra de población española con DM1, no se ha hallado asociación entre el genotipo de Hp y el riesgo de ND

Damage function for historic paper. Part II: Wear and tear

Background: As a result of use of library and archival documents, defined as reading with handling in the context of general access, mechanical degradation (wear and tear) accumulates. In contrast to chemical degradation of paper, the accumulation of wear and tear is less well studied. Previous work explored the threshold of mechanical degradation at which a paper document is no longer considered to be fit for the purpose of use by a reader, while in this paper we explore the rate of accumulation of such damage in the context of object handling. Results: The degree of polymerisation (DP) of historic paper of European origin from mid-19th–mid-20th Century was shown to affect the rate of accumulation of wear and tear. While at DP > 800, this accumulation no longer depends on the number of handlings (the process is random), a wear-out function could be developed for documents with DP between 300 and 800. For objects with DP < 300, one large missing piece (i.e. such that contains text) developed on average with each instance of handling, which is why we propose this DP value as a threshold value for safe handling. Conclusions: The developed model of accumulation of large missing pieces per number of handlings of a document depending on DP, enables us to calculate the time required for an object to become unfit for use by readers in the context of general access. In the context of the average frequency of document use at The UK National Archives (Kew), this period is 60 years for the category of papers with DP 300, and 450 years for papers with DP 500. At higher DP values, this period of time increases beyond the long-term planning horizon of 500 years, leading to the conclusion that for such papers, accumulation of wear and tear is not a significant collection management concern

Active wetting of epithelial tissues

Development, regeneration and cancer involve drastic transitions in tissue morphology. In analogy with the behavior of inert fluids, some of these transitions have been interpreted as wetting transitions. The validity and scope of this analogy are unclear, however, because the active cellular forces that drive tissue wetting have been neither measured nor theoretically accounted for. Here we show that the transition between 2D epithelial monolayers and 3D spheroidal aggregates can be understood as an active wetting transition whose physics differs fundamentally from that of passive wetting phenomena. By combining an active polar fluid model with measurements of physical forces as a function of tissue size, contractility, cell-cell and cell-substrate adhesion, and substrate stiffness, we show that the wetting transition results from the competition between traction forces and contractile intercellular stresses. This competition defines a new intrinsic lengthscale that gives rise to a critical size for the wetting transition in tissues, a striking feature that has no counterpart in classical wetting. Finally, we show that active shape fluctuations are dynamically amplified during tissue dewetting. Overall, we conclude that tissue spreading constitutes a prominent example of active wetting --- a novel physical scenario that may explain morphological transitions during tissue morphogenesis and tumor progression

Human sperm swimming in a high viscosity mucus analogue

Remarkably, mammalian sperm maintain a substantive proportion of their progressive swimming speed within highly viscous fluids, including those of the female reproductive tract. Here, we analyse the digital microscopy of a human sperm swimming in a highly viscous, weakly elastic mucus analogue. We exploit principal component analysis to simplify its flagellar beat pattern, from which boundary element calculations are used to determine the time-dependent flow field around the sperm cell. The sperm flow field is further approximated in terms of regularized point forces, and estimates of the mechanical power consumption are determined, for comparison with analogous low viscosity media studies. This highlights extensive differences in the structure of the flows surrounding human sperm in different media, indicating how the cell-cell and cell- boundary hydrodynamic interactions significantly differ with the physical microenvironment. The regularized point force decomposition also provides cell-level information that may ulti- mately be incorporated into sperm population models. We further observe indications that the core feature in explaining the effectiveness of sperm swimming in high viscosity media is the loss of cell yawing, which is related with a greater density of regularized point force singularities along the axis of symmetry of the flagellar beat to represent the flow field. In turn this implicates a reduction of the wavelength of the distal beat pattern – and hence dynamical wavelength selection of the flagellar beat – as the dominant feature governing the effectiveness of sperm swimming in highly viscous media

Interactivity Improves Usability of Geographic Maps for Visually Impaired People

International audienceTactile relief maps are used by visually impaired people to acquire mental representation of space, but they retain important limitations (limited amount of information, braille text, etc.). Interactive maps may overcome these limitations. However, usability of these two types of maps had never been compared. It is then unknown whether interactive maps are equivalent or even better solutions than traditional raised-line maps. This study presents a comparison of usability of a classical raised-line map vs. an interactive map composed by a multi-touch screen, a raised-line overlay and audio output. Both maps were tested by 24 blind participants. We measured usability as efficiency, effectiveness and satisfaction. Our results show that replacing braille with simple audio-tactile interaction significantly improved efficiency and user satisfaction. Effectiveness was not related to the map type but depended on users' characteristics as well as the category of assessed spatial knowledge. Long-term evaluation of acquired spatial information revealed that maps, whether interactive or not, are useful to build robust survey-type mental representations in blind users. Altogether, these results are encouraging as they show that interactive maps are a good solution for improving map exploration and cognitive mapping in visually impaired people