256 research outputs found

    Modulation instability and conservation of energy:toward a new model

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    L'articolo analizza la propagazione in regime nonlineare di un segnale ottico CW in presenza di una "piccola" perturbazione. In letteratura sono presenti lavori che specificano i parametri fisici che regolano l'interazione tra il segnale CW e la perturbazione ma non si hanno indicazioni relative ai limiti di applicabilità dei modelli proposti. Obiettivo principale di questo lavoro è rappresentato dalla definizione dei parametri che "attivano" l'instabilità di modulazione e regolano il regime di propagazione nonlineare. A tal fine, il regime di propagazione nonlineare è analizzato vincolandolo al principio di conservazione dell'energia

    Inclusive University didactics and technological devices: a case study

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    This paper provides a review of projects related to new technologies used to favour the teaching-learning processes and the inclusive practices in the University context for students with disabilities and with Specific Learning Disorders. Authors present a review of strategies, trajectories and perspectives activated in the national and international scene, aiming to guarantee a significant pedagogical framework of reference. Furthermore, the paper focuses on a meaningful path activated at the University of Macerata, the project Inclusion 3.0, a relevant example of new technologies in support of teaching- learning processes and inclusion practices among all students

    Role of post mortem CT (PMCT) in high energy traumatic deaths

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    Background. Post Mortem Computed Tomography (PMCT) is being increasingly implemented in forensic field and could be an adjuvant to classic autopsies. In this study we evaluated the feasibility of complementation of conventional autopsy in trauma victims with PMCT. Materials and methods. A total of 21 subjects, who had sustained various types of blunt high-energy trauma, were selected from the casuistry of the Section of Legal Medicine at University of Pisa: before autopsy, a PMCT examination (Toshiba Aquilion 16 CT scanner) was performed, and after the acquisition of the raw images, MPR and VR reconstructions were performed with dedicated software. Results. PMCT is more sensitive than conventional autopsy in detecting skeletal injuries, whilst autopsy constitutes the method of choice for the detection of thoracic and abdominal visceral injuries. Conclusion. PMCT should be considered a useful tool in addition to conventional autopsy in evaluating trauma victims: it detects further bone fractures in body parts difficult to investigate during autopsy (i.e. posterior regions), facilitating the pathologist in the reconstruction of events and in determining the cause of death

    Characterization of gaze in handwriting of High and Low Frequency Word of Schoolchildren with Dyslexia

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    Writing is extremely important for our academic and professional life and can affect our performance in productive educational activities, favouring us or not. Schoolchildren with dyslexia bring difficulties and reduced school performance due to their condition of deprivation in written production. This is because schoolchildren with dyslexia have difficulty acquiring spelling knowledge and show poor phonological skills. This study aimed to characterize the performance of schoolchildren with dyslexia in “gaze” for the handwriting of High and Low-frequency words. A total of 24 schoolchildren participated in the study. They were between 8 to 11 years and 11 months of age, of both sexes, and they were attending the 3rd to the 5th year of Elementary School in the city of Marília-SP. The schoolchildren were divided into groups: GI, composed of 12schoolchildren with an interdisciplinary diagnosis of developmental dyslexia, and GII, composed of 12 schoolchildren with good academic performance, paired with GI according to the school grade level. These schoolchildren were submitted to computerized handwriting evaluation using a Brazilian adaptation of the Software Ductus. All schoolchildren were submitted to a copy of words already selected according to Brazilian Portuguese criteria of frequency and codification rule. A measure of “gaze” was used, that is, when the schoolchildren stopped their handwriting to search/look up at the screen to confirm the information about the words. The results indicated a significant difference between GI and GII, with GI schoolchildren performing more gaze when compared with GII, i.e., taking longer motor breaks to perform the gaze. Therefore, there was a rupture in the central processing with the peripheral when the child performed the gauze more times since he had to confirm the characteristics of this word during the writing process (difficulty in accessing the orthographic lexicon) and with that, there was a break in the movement of handwriting (since there was not enough information in the central plane to complete that motor memory and finish the word). It was concluded that there were gaps between the central (orthographic) and peripheral (motor pauses processes, suggesting deficits in the formation of motor programs for GI and the lack of automation of motor processes

    Speed and pressure of handwriting as critical issues of the contemporary age: A research in Italian students in early literacy

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    Among the present critical issues that pedagogy and special teaching have to deal with it is possible to notice the contrast between writing and technology, up to the pertinent field of prevention and observation of dysgraphies. The authors present in the following article a study conducted in Italy aimed at evaluating writing, specifically in the speed and pressure parameters in early literacy using NeuroScript Movalyzer Software. The aim is to implement suitable research paths to support the dissemination of observation procedures and inclusive teaching practices, capable of enhancing the fluidity of writing by all students

    Direct detection of spin polarization in photoinduced charge transfer through a chiral bridge

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    It is well assessed that the charge transport through a chiral potential barrier can result in spin-polarized charges. The possibility of driving this process through visible photons holds tremendous potential for several aspects of quantum information science, e.g., the optical control and readout of qubits. In this context, the direct observation of this phenomenon via spin-sensitive spectroscopies is of utmost importance to establish future guidelines to control photo-driven spin selectivity in chiral structures. Here, we provide direct proof that time-resolved electron paramagnetic resonance (EPR) can be used to detect long-lived spin polarization generated by photoinduced charge transfer through a chiral bridge. We propose a system comprising CdSe quantum dots (QDs), as a donor, and C60, as an acceptor, covalently linked through a saturated oligopeptide helical bridge (χ) with a rigid structure of ∼10 Å. Time-resolved EPR spectroscopy shows that the charge transfer in our system results in a C60 radical anion, whose spin polarization maximum is observed at longer times with respect to that of the photogenerated C60 triplet state. Notably, the theoretical modelling of the EPR spectra reveals that the observed features may be compatible with chirality-induced spin selectivity, but the electronic features of the QD do not allow the unambiguous identification of the CISS effect. Nevertheless, we identify which parameters need optimization for unambiguous detection and quantification of the phenomenon. This work lays the basis for the optical generation and direct manipulation of spin polarization induced by chirality
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