371 research outputs found
Multisensory-Based Rehabilitation Approach: Translational Insights from Animal Models to Early Intervention
Multisensory processes permit combinations of several inputs, coming from different sensory systems, allowing for a coherent representation of biological events and facilitating adaptation to environment. For these reasons, their application in neurological and neuropsychological rehabilitation has been enhanced in the last decades. Recent studies on animals and human models have indicated that, on one hand multisensory integration matures gradually during post-natal life and development is closely linked to environment and experience and, on the other hand, that modality-specific information seems to do not benefit by redundancy across multiple sense modalities and is more readily perceived in unimodal than in multimodal stimulation. In this review, multisensory process development is analyzed, highlighting clinical effects in animal and human models of its manipulation for rehabilitation of sensory disorders. In addition, new methods of early intervention based on multisensory-based rehabilitation approach and their applications on different infant populations at risk of neurodevelopmental disabilities are discussed
Ninety years of publications in Economic History: evidence from the top five field journals (1927-2017)
The growing appeal of the long run perspective among economists and the fiftieth anniversary of the of the publication of the Conrad and Meyer article (1958), which signed the Cliometric Revolution, have attracted a lot of interest on the origin and the development of Economic history. This paper explores the evolution of the field with a new articulated database of all the 6,516 articles published in five journals (Economic History Review, Journal of Economic History, Explorations in Economic History, European Review of Economic History and Cliometrica) from their establishment to 2017. We show that these journals are the most important in the field, with a wide influence also outside it. Our main results are that the Cliometric Revolution took quite a long time to fully display its effects, which became evident only in the 1990s, when personal computer and software packages became available. Finally, as for the last two decades, we find that the process of integration of economic history into economics is, so far, slower than previously suggested and limited to US. On the other hand, the most striking and neglected change is the overall success of Continental European scholars within the field. Are these changes the harbinger of a new divergence between the two shores of the Atlantic with the rise of a new paradigm based on the “Historical economics” approach? It is too early to tell
Effects of Sucrose on the Internal Dynamics of Azurin
AbstractSucrose is a natural osmolyte accumulated in cells of organisms as they adapt to environmental stresses. In vitro, sucrose increases protein stability and forces partially unfolded structures to refold. Its effects on the native fold structure and dynamics are not fully established. This study, utilizing Trp phosphorescence spectroscopy, examined the influence of molar concentrations of sucrose on the flexibility of metal-free azurin from Pseudomonas aeruginosa. In addition, by means of specific mutants of the test protein, namely I7S, F110S, and C3A/C26A, that altered its thermodynamic stability, its intrinsic flexibility, and the extent of internal hydration, this investigation sought to identify possible correlations between these features of protein structure and the influence of the osmolyte on protein dynamics. Alterations of structural fluctuations were assessed by both the intrinsic phosphorescence lifetime (Ď„), which reports on local structure about the triplet probe, and the acrylamide bimolecular quenching rate constant (kq) that is a measure of the average acrylamide diffusion coefficient through the macromolecule. From the modulation of Ď„ and kq across a wide temperature range and up to a concentration of 2M sucrose, it is concluded that sucrose attenuates structural fluctuations principally when macromolecules are internally hydrated and thermally expanded. Preliminary tests with trehalose and xylitol suggest that the effects of sucrose are general of the polyol class of osmolytes
Impaired Visual Size-Discrimination in Children with Movement Disorders.
Abstract Multisensory integration of spatial information occurs late in childhood, at around eight years ( Gori, Del Viva, Sandini, & Burr, 2008 ). For younger children, the haptic system dominates size discrimination and vision dominates orientation discrimination: the dominance may reflect sensory calibration, and could have direct consequences on children born with specific sensory disabilities. Here we measure thresholds for visual discrimination of orientation and size in children with movement disorders of upper limbs. Visual orientation discrimination was very similar to the age-matched typical children, but visual size discrimination thresholds were far worse, in all eight individuals with early-onset movement disorder. This surprising and counterintuitive result is readily explained by the cross-sensory calibration hypothesis: when the haptic sense is unavailable for manipulation, it cannot be readily used to estimate size, and hence to calibrate the visual experience of size: visual discrimination is subsequently impaired. This complements a previous study showing that non-sighted children have reduced acuity for haptic orientation, but not haptic size, discriminations ( Gori, Sandini, Martinoli, & Burr, 2010 ). Together these studies show that when either vision or haptic manipulation is impaired, the impairment also impacts on complementary sensory systems that are calibrated by that one
Concurrent and predictive validity of the infant motor profile in infants at risk of neurodevelopmental disorders
BACKGROUND: Preterm infants and infants with perinatal brain injury show a higher incidence of neurodevelopmental disorders (NDD). The Infant Motor Profile (IMP) is a clinical assessment which evaluates the complexity of early motor behaviour. More data are needed to confirm its predictive ability and concurrent validity with other common and valid assessments such as the Alberta Infant Motor Scale (AIMS) and Prechtl's General Movement Assessment (GMA). The present study aims to evaluate the concurrent validity of the IMP with the AIMS, to assess its association with the GMA, to evaluate how the IMP reflects the severity of the brain injury and to compare the ability of the IMP and the AIMS to predict an abnormal outcome in 5-month-old infants at risk of NDD.METHODS: 86 infants at risk of NDD were retrospectively recruited among the participants of two clinical trials. Preterm infants with or without perinatal brain injury and term infants with brain injury were assessed at 3months corrected age (CA) using the GMA and at 5months CA using the IMP and the AIMS. The neurodevelopmental outcome was established at 18months.RESULTS: Results confirm a solid concurrent validity between the IMP Total Score and the AIMS (Spearman's rho 0.76; p<.001) and a significant association between IMP Total Score and the GMA. Unlike the AIMS, the IMP Total score accurately reflects the severity of neonatal brain injury (p<.001) and proves to be the strongest predictor of NDD (p<.001). The comparison of areas under receiver operating characteristic curves (AUC) confirms that the IMP Total score has the highest diagnostic accuracy at 5months (AUC 0.92). For an optimal IMP Total Score cut-off value of 70, the assessment shows high sensitivity (93%) and specificity (81%) (PPV 84%; NPV 90%).CONCLUSIONS: Early motor behaviour assessed with the IMP is strongly associated with middle-term neurodevelopmental outcome. The present study confirms the concurrent validity of the IMP with the AIMS, its association with the GMA and its ability to reflect brain lesion load, hence contributing to the construct validity of the assessment.TRIAL REGISTRATION: NCT01990183 and NCT03234959 (clinicaltrials.gov)
Machine learning of microscopic structure-dynamics relationships in complex molecular systems
In many complex molecular systems, the macroscopic ensemble's properties are
controlled by microscopic dynamic events (or fluctuations) that are often
difficult to detect via pattern-recognition approaches. Discovering the
relationships between local structural environments and the dynamical events
originating from them would allow unveiling microscopic level
structure-dynamics relationships fundamental to understand the macroscopic
behavior of complex systems. Here we show that, by coupling advanced structural
(e.g., Smooth Overlap of Atomic Positions, SOAP) with local dynamical
descriptors (e.g., Local Environment and Neighbor Shuffling, LENS) in a unique
dataset, it is possible to improve both individual SOAP- and LENS-based
analyses, obtaining a more complete characterization of the system under study.
As representative examples, we use various molecular systems with diverse
internal structural dynamics. On the one hand, we demonstrate how the
combination of structural and dynamical descriptors facilitates decoupling
relevant dynamical fluctuations from noise, overcoming the intrinsic limits of
the individual analyses. Furthermore, machine learning approaches also allow
extracting from such combined structural/dynamical dataset useful
microscopic-level relationships, relating key local dynamical events (e.g.,
LENS fluctuations) occurring in the systems to the local structural (SOAP)
environments they originate from. Given its abstract nature, we believe that
such an approach will be useful in revealing hidden microscopic
structure-dynamics relationships fundamental to rationalize the behavior of a
variety of complex systems, not necessarily limited to the atomistic and
molecular scales
Cortical thickness of primary visual cortex correlates with motion deficits in periventricular leukomalacia
Abstract Impairments of visual motion perception and, in particular, of flow motion have been consistently observed in premature and very low birth weight subjects during infancy. Flow motion information is analyzed at various cortical levels along the dorsal pathways, with information mainly provided by primary and early visual cortex (V1, V2 and V3). We investigated the cortical stage of the visual processing that underlies these motion impairments, measuring Grey Matter Volume and Cortical Thickness in 13 children with Periventricular Leukomalacia (PVL). The cortical thickness, but not the grey matter volume of area V1, correlates negatively with motion coherence sensitivity, indicating that the thinner the cortex, the better the performance among the patients. However, we did not find any such association with either the thickness or volume of area MT, MST and areas of the IPS, suggesting damage at the level of primary visual cortex or along the optic radiation
Gate-Bias Induced RON Instability in p-GaN Power HEMTs
In this letter, we investigate the on-resistance ( RON ) instability in p-GaN power HEMTs induced by a positive or negative gate bias ( VGB ), following the application of a quasi-static initialization voltage ( VGP ) of opposite sign. The transient behavior of this instability was characterized at different temperatures in the 90–135 °C range. By monitoring the resulting drain current transients, the activation energy as well as time constants of the processes are characterized. Not trivially, both RON increase/decrease were found to be thermally activated and with same activation energy. We attribute the thermal activation of both RON increase/decrease to the charging/discharging of hole traps present in the AlGaN barrier in the region below the gate
Hypermethylation ofHOXA10gene in mid-luteal endometrium from women with ovarian endometriomas
A new system for quantitative evaluation of infant gaze capabilities in a wide visual field.
Background: The visual assessment of infants poses specific challenges: many techniques that are used on adults are based on the patient’s response, and are not suitable for infants. Significant advances in the eye-tracking have made this assessment
of infant visual capabilities easier, however, eye-tracking still requires the subject’s collaboration, in most cases and thus limiting the application in infant research. Moreover, there is a lack of transferability to clinical practice, and thus it emerges the need for a new tool to measure the paradigms and explore the most common visual competences in a wide visual field. This work presents the design, development and preliminary testing of a new system for measuring infant’s gaze in the wide visual field called CareToy C: CareToy for Clinics.
Methods: The system is based on a commercial eye tracker (SmartEye) with six cameras running at 60 Hz, suitable for measuring an infant’s gaze. In order to stimulate the infant visually and audibly, a mechanical structure has been designed to support five speakers and five screens at a specific distance (60 cm) and angle: one in the centre, two on the right-hand side and two on the left (at 30° and 60° respectively). Different tasks have been designed in order to evaluate the system capability to assess the infant’s gaze movements during different conditions (such as gap, overlap or audiovisual paradigms). Nine healthy infants aged 4–10 months were assessed as they performed the visual tasks at random.
Results: We developed a system able to measure infant’s gaze in a wide visual field covering a total visual range of ±60° from the centre with an intermediate evaluation at ±30°. Moreover, the same system, thanks to different integrated software, was able
to provide different visual paradigms (as gap, overlap and audio-visual) assessing and comparing different visual and multisensory sub-competencies. The proposed system endowed the integration of a commercial eye-tracker into a purposive setup in a smart and innovative way.
Conclusions: The proposed system is suitable for measuring and evaluating infant’s gaze capabilities in a wide visual field, in order to provide quantitative data that can enrich the clinical assessment
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