302 research outputs found

    A Theoretical Analysis of the Influence of Fixational Instability on the Development of Thalamocortical Connectivity

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    Under natural viewing conditions, the physiological inotability of visual fixation keeps the projection of the stimulus on the retina in constant motion. After eye opening, chronic exposure to a constantly moving retinal image might influence the experience-dependent refinement of cell response characteristics. The results of previous modeling studies have suggested a contribution of fixational instability in the Hebbian maturation of the receptive fields of V1 simple cells (Rucci, Edelman, & Wray, 2000; Rucci & Casile, 2004). This paper presents a mathematieal explanation of our previous computational results. Using quasi-linear models of LGN units and V1 simple cells, we derive analytical expressions for the second-order statistics of thalamocortical activity before and after eye opening. We show that in the presence of natural stimulation, fixational instability introduces a spatially uncorrelated signal in the retinal input, whieh strongly influences the structure of correlated activity in the model

    Nouvelles technologies de l’information et de la communication et anciens instruments de régulation : l’exemple d’Internet en France

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    L’étude de la jurisprudence française relative à Internet entre 1996 et 1997 montre que, loin d’être un « espace de non-droit », le réseau des réseaux est assujetti au respect de règles juridiques. Ainsi, l’exemple de l’exercice de la liberté d’expression met en exergue que le droit français peut s’appliquer à Internet comme à tout autre vecteur de communication, même si l’édifice jurisprudentiel paraît encore fragile. Quant aux droits intellectuels, le juge français, s’il doit respecter les textes applicables, doit également tenir compte de l’esprit libéral du réseau.A study of the case law regarding French language use on the Internet during 1996 and 1997 demonstrates that, far from being a non-legal issue, the network requires juridical boundaries. For example, the exercise of freedom of expression highlights the fact that French law can be applied to the Internet as it does to other vehicles of communication, regardless of the continuing ambiguity surrounding legal provision in this area. As to intellectual rights, in the French context, a judge is obliged to respect existing legal texts as well as the liberal spirit of the network

    Sullivan County Board of Tourism Strategic Recommendations

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    The Sullivan County Tourism Commission set forth the objective to identify strategies for increasing tourism year-round in Sullivan County and Sullivan. The BUS 401 course students were placed in three groups and set to provide end deliverables of these strategies. The demographics of the population underscored some important populations to target with identified strategies of surveying and a punch card system

    GNSS interference management techniques against malicious attacks

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    This thesis collects the outcomes of a Ph.D. course in Telecommunications Engineering and it is focused on the study and design of possible techniques able to counteract interference signal in Global Navigation Satellite System (GNSS) systems. The subject is the jamming threat in navigation systems, that has become a very increasingly important topic in recent years, due to the wide diffusion of GNSS-based civil applications. Detection and mitigation techniques are developed in order to fight out jamming signals, tested in different scenarios and including sophisticated signals. The thesis is organized in two main parts, which deal with management of GNSS intentional counterfeit signals. The first part deals with the interference management, focusing on the intentional interfering signal. In particular, a technique for the detection and localization of the interfering signal level in the GNSS bands in frequency domain has been proposed. In addition, an effective mitigation technique which exploits the periodic characteristics of the common jamming signals reducing interfering effects at the receiver side has been introduced. Moreover, this technique has been also tested in a different and more complicated scenario resulting still effective in mitigation and cancellation of the interfering signal, without high complexity. The second part still deals with the problem of interference management, but regarding with more sophisticated signal. The attention is focused on the detection of spoofing signal, which is the most complex among the jamming signal types. Due to this highly difficulty in detect and mitigate this kind of signal, spoofing threat is considered the most dangerous. In this work, a possible techniques able to detect this sophisticated signal has been proposed, observing and exploiting jointly the outputs of several operational block measurements of the GNSS receiver operating chain

    The Upper Extremity Functional Index (UEFI). Cross-cultural adaptation, reliability, and validity of the italian version

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    SUMMARY Introduction. The Italian version of the Upper Extremity Functional Index (UEFI) may help assess shoulder function in patients with shoulder problems, especially athletes. Objective. Translate and cross-culturally adapt UEFI into Italian; verify UEFI validity and reliability in professional and amateur athletes with upper limb musculoskeletal disorders, shoulder, in particular. Methods. This study was conducted with 150 participants with musculoskeletal disorders of the upper limb. UEFI, the short version of the Disability of the Arm, Shoulder and Hand scale (Quick DASH), the Shoulder Pain and Disability Index, and the Short Form-36 Health Survey (SF-36) were administered. Acceptability was assessed in terms of refusal rate, rates of missing responses, and administration time; test-retest reliability was assessed with intraclass correlation coefficient (ICC); internal consistency was assessed with Cronbach’s alpha coefficient, and validity was assessed by Pearson’s correlation coefficients. Results. Cronbach’s alpha coefficients for the UEFI on test and retest were α = 0.979 and α = 0.985, respectively. The average measure ICC was 0.917. The UEFI score demonstrated strong negative correlations with SPADI total score (-0.636), Quick DASH score (-0.685), and SF-36 score (-0.327). Conclusions. The Italian version of UEFI is acceptable, valid, and reliable

    Glucometer Usability for 65+ Type 2 Diabetes Patients: Insights on Physical and Cognitive Issues

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    Background: Self-monitoring of blood glucose (SMBG) is of paramount relevance for type 2 diabetes mellitus (T2DM) patients. However, past evidence shows that there are physical and cognitive issues that might limit the usage of glucometers by T2DM patients aged 65 years and over. Objective: Our aim was to investigate the physical and cognitive issues related to the usage of glucometers by T2DM patients aged 65 years and over. Materials and Methods: The extant literature was analysed to define an original framework showing the logical nexus between physical and cognitive issues and quality of life. Then we collected evidence addressing the specific case of the Accu-Chek® Instant glucometer produced by Roche Diabetes Care GmbH, which implements new features claiming to improve usability. We conducted 30 interviews with T2DM patients aged 65 years and over, three interviews with senior nurses, and a focus group with three senior physicians and three senior nurses. Results: From the interviews, both patients and nurses declared that they were generally satisfied with the Accu-Chek® Instant glucometer’s characteristics. In the focus group, the results were commented on and, in the light of some diverging answers, improvements have been set up for future implementation. Conclusions: Our study produces evidence and future suggestions about the usage of glucometers by type 2 diabetes patients aged 65 years and over

    View-Based Encoding of Actions in Mirror Neurons of Area F5 in Macaque Premotor Cortex

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    SummaryConverging experimental evidence indicates that mirror neurons in the monkey premotor area F5 encode the goals of observed motor acts [1–3]. However, it is unknown whether they also contribute to encoding the perspective from which the motor acts of others are seen. In order to address this issue, we recorded the visual responses of mirror neurons of monkey area F5 by using a novel experimental paradigm based on the presentation of movies showing grasping motor acts from different visual perspectives. We found that the majority of the tested mirror neurons (74%) exhibited view-dependent activity with responses tuned to specific points of view. A minority of the tested mirror neurons (26%) exhibited view-independent responses. We conclude that view-independent mirror neurons encode action goals irrespective of the details of the observed motor acts, whereas the view-dependent ones might either form an intermediate step in the formation of view independence or contribute to a modulation of view-dependent representations in higher-level visual areas, potentially linking the goals of observed motor acts with their pictorial aspects
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